Hello everyone!

Hey guys. I'm quite new here so if this isn't the right place to post, go easy on me please. :) I'm quite a big guy and have been for most of my life, But recently I've noticed that my waist is getting a little bit big. I've got stretch marks, which I don't know if it's from the exercises I'm doing stretching the skin, or the weight gain, probably the latter, but I'd like to somehow stay the same weight and trim my waist down a tiny bit. I know this is impossible without losing fat, but is there any way I can achieve this while gaining weight/muscle? It's bumming me out cause I look okay everywhere else. Thanks everyone.