Wtf should I think!?

First of all, this is not something that just randomly happened all of a sudden, its more like a here and there thing that’s been happening for about a year maybe. But long story short, my boyfriend of 4 years and father to my son has been taking my panties to wear then keeping them all hid somewhere. I’ve found them many different times in different places and several other things that more than likely play a part in his “activity’s”. At first I just brushed it off but I can’t do that anymore. It’s got my mind running constantly and idk what to do, say or even think.