How can I stop making assumptions?

Are these guys making fun of me?

• So I'm 20 and where I work there are security guys that work there too. I usually don't talk to them, because I'm a pretty shy and quiet person and tend to keep to myself. There's a few I say hi to and one I actually talk to because I've known him for years and we are friends. They were by their work station/ office all together at the end of the day just messing around, talking, and finishing up or whatever. I was walking by because the restrooms are by their work area, anyways, I say "hi" to the one I'm friends with and he says "hi" back, gesturing me a 'high five'. We hi five and say goodbye; he tells me to say hello to the family. I politely say good-bye to all, even though my intuition tells me most of them send off bad vibes for some reason I can't quite pinpoint. After I get out of the restroom, and they are still there. They seem busy so I just smile at all present politely, so as not to disturb. When walking off, my friend yells "bye". I turn and say "bye" back. They get all quiet for a second as I am walking away, then they all start laughing. They stop and it sounds like they are speaking then cue. explosive laughter once again. I felt kind of uncomfortable immediately because I felt like if they were probably talking about me, for some reason. And it really bothers me to think that they might be making fun, or be making erroneous assumptions about me. I have to see these people constantly and don't want to have to be dealing with it. I feel like they've done this before, because they tend to laugh when I'm done talking with my friend in more than one occasion. I don't know what to think anymore and maybe I'm just being a bit paranoid/stupid, but something doesn't feel right. Ughhh!! What do you think?! Much thanks (:

• Answer:

  I kind feel that they maybe making fun of you,but since you need to face them everyday it best you try to say "HI" or talk to all the guys. Beign friend to just one guy could be the main cause of the problem.Maybe the next time try smiling at all of them and say "HI GUYS" look at all of them instead of just focusing on your one friend .However it will take time for them to change the approach towards you as well.