What's between letting things go and leaving over them?

It's not boundaries, but assertiveness that you need to work on. Assertiveness is different from enforcing a point of view. When you are assertive, the other person takes you seriously, not because you will do something to them otherwise, but because of how you express yourself.

You need to stop asking and just find a solution and do it. For example, move into the spare bedroom tonight. Inform him you will be happy to sleep in the same bed again just as soon as he has found a solution to the snoring. Do not be bitchy or mad. Do not withold sex. Vindictiveness is not going to solve anything. But stop asking and stop trying to manipulate his behavior. Instead, start taking action. Next time he hurts you during a massage, the massage is simply over. Period. If you have two bathrooms, declare one yours and one his. He can dribble on his floor all he likes and clean it up whenever he feels like it. You are no longer cleaning his bathroom and if you use his bathroom you won't complain about the mess. He cannot use your bathroom. If he does not respect this boundary, buy a lock with a key for your bathroom and install it yourself or pay someone else or get a friend to do it. Do not give him the key. If physically enforcing your own boundaries causes him to push back and try all the harder to literally and figuratively piss on you, that's the time to seriously consider leaving. Some people have a very hard time changing. But if you can find a real solution that you can implement with minimal imposition on their poor memory or other weak area, they are fine with it. But abusive people aren't fine with it when you find a real solution. Once you know which kind of person you are married to, it makes it tons easier to decide what to do next.

Your husband knows you won't do anything. He knows if he says the right words, makes it seem as if he's trying, he won't have to actually put forth the effort to change anything. In a way, he's calling your bluff. Do what DarlingBri and Michele in California suggested. Stop asking nicely and put the consequences in action. Say you're fucking tired of dealing with X and until it's fixed, you're going to sleep in the spare/he can only use one of two bathrooms. (Also wtf if someone is hurting you during a massage and moving your arms when you try to shield yourself, you absolutely flip out and get up and walk away. Then you get angry at them. Don't accept an apology easily - he was willfully and knowingly hurting you!) Dumping someone isn't the only consequence for boundary-violating behaviour. A good midpoint is removing yourself from their company until they shape up, saying that you don't want to be around them so long as they continue to do X. If they continue to do X, then they've just told you that they don't care about your wishes. Do with that what you will.

I tend to view everything in life as negotiable, and that applies to relationships too. If I want something out of a relationship that my partner doesn't want to give me, I need to offer them an incentive that I might not otherwise give. Likewise, if my partner wants something out of the relationship that I'm not interested in, they need to offer me an incentive. If the thing in question is really difficult for one person, then whomever wants it needs to make a good offer. For example, seeing my significant other every day is something that I would rather not do, but it's not a big deal to me. For me to agree to something like this, I'd probably ask for something like my partner preparing a meal for me every other day, so that I have more time to fit them into my schedule. On the other hand, if it were something like asking for an open relationship (I'm naturally monogamous) I would ask for a ton of restrictions and rules to make sure I was getting a good deal and that my partner wasn't neglecting me or getting much more sex than I was. The take-away from this is that before you ask for something, you need to think about how big a deal it is to your partner and what you might be able to offer in exchange. If you aren't prepared to offer something for it, then you're not negotiating, you're demanding - and your partner is fully within their rights to ignore demands. Disclaimer - this is not meant to justify your husband's behavior: he sounds very insensitive and I can see why you'd be upset. My point is that your question came off to me as somewhat entitled because you are framing this as "How can I change him?" as opposed to "What can I offer him to get him to want to change?"

I think you need to let go of the backrub issue. You explicitly told him he could keep pressing there if he did so more gently. He can't read your mind and understand exactly how hard is too hard. This is not a failure of empathy. He's guessing, and guesses are imperfect. Pain is sometimes a natural consequence of well-intended actions; that's just life. You're free to end the massage when it's no longer good for you, but it doesn't make sense to hold a grudge over this. The piss and the sleep apnea seem like much more important issues to tackle, and they're not easy ones. All I can offer is that you should remember to say positive things about behaviors you like much more often than you complain about things you don't like. If he's ever going to do these things regularly it will because doing them makes him feel good, not because you've made him feel bad every time he didn't do them.

When I started to cry, he stopped, apologised and comforted me. But then he said "I should have remembered that you wouldn't say anything until it was already too much." Still crying, I not-quite-yelled at him that I didn't know what could be clearer than "Ow! Stop! That really hurts. I need you to be much more gentle in that spot or not touch it!" To be honest, there is something really weird and off to me about your husband's behavior here. In particular, his first "apology" struck me as extremely manipulative/gaslighting. Maybe he's not intentionally being manipulative, maybe there is something else that's just off, maybe he has problems processing... something or other. But I don't know. Is this the only occasion where he's said something negative yet demonstrably false about you, to turn something that's his fault into your failing? I also think jon1270 was totally right about this: Your husband knows you won't do anything. He knows if he says the right words, makes it seem as if he's trying, he won't have to actually put forth the effort to change anything. In a way, he's calling your bluff.

PS-Sleep Apnea can and does cause depression too. It affects just about every aspect of your life. I cannot stress enough just how much better his life will be if he will take action!

Ditto that the massage thing is worrisome. It gave me the nudge I needed to tell my husband that he was responsible for checking in front of the loo and cleaning up after himself. Well, now it's months later and I'm still getting damp toes or finding drips scattered around the toilet most nights. Mostly I ask him to stop what he's doing ASAP/get out of bed and come clean it, but sometimes I just tell him about it while I wipe things up myself because it seems like more trouble than it's worth to get him up for a job I can do in two seconds. He gets sad and self-critical about how he looked but didn't see anything to clean, but can see it when I'm standing there demanding he look again. I know noticing messes in the house is a learned skill and he isn't going to pick it up overnight, but I'm tired of nagging him about it. It can't be fun for him either. Okay... So, if you approach your husband with a problem and get an agreement out of him to take care of it, and then you wind up taking care of it yourself, you are undermining yourself in a big way because you're showing him that you're not entirely serious about the agreement you're asking him to make. You're showing him that the way to placate you is to tell you what you want to hear, and that the follow-through isn't that big of a deal. The thing is that it ISN'T more trouble than it's worth for you to go to him and ask him to take care of it. That, in essence, is what he's agreeing to when he agrees to be responsible for it. He should be thinking that it's "more trouble than it's worth" to slack off when it comes to this after hearing you complain about it and recognizing that it's something that's clearly on his side of the line. The sadness and self-criticism strike me as manipulative. Get at the root of whatever the problem is here. If he's "having trouble noticing," get him on a schedule, like cleaning every single time, or to sit when he does his business, or have him use a different bathroom, or trade you for a chore that you hate doing. And press him every time there continues to be a problem so that he knows you mean business when you come to him with an issue. This isn't you being nagging; it's you expecting him to follow up with his end of the agreements he makes with you; it's you merely insisting that he communicates honestly with you. You might want to read Crucial Confrontations, to be sure that there isn't something about the way you're approaching the conversation that isn't making the problem worse.

In your examples, I don't see any boundaries, only needs. Boundaries are "if X happens, I will do Y." What makes that different than an ultimatum is that a ultimatum is "if YOU do/don't do X then I will do Y". Ultimatums give the power to someone other than you. So with your sleep apnea example (I get that it's an example, but I'm using it for simplicity's sake): Boundary: "I don't sleep in the same room with people who snore. If someone is snoring, I move to another room." Then, when he snores, move. Ultimatum: "If you don't get a sleep apnea test, I'm moving to the spare bedroom."