Bonus question: how do you tell someone to back tf up without being rude lol

If you aren’t my child, pet or lover I need my space! 😂 I have a friend (bless his heart) that just doesn’t know what personal space is. We could have a whole couch to ourselves & he will sit right next to me, thigh to thigh (before you say it, he’s 100% gay I think he just doesn’t know boundaries & loves me so he wants to be close) it drives me insane but I feel so mean thinking about it 😭

I mentally cannot deal with people in my space, my body gets hot & I get jittery & no matter how much I move from him, he still finds a way to be near me. I also have a problem with hearing/ feeling people breathe, eat (or any mouth noises) and he breathes hard, loud & close as fuck to me. I hope y’all don’t think I’m trying to be mean I just genuinely don’t know how to approach him about it since he’s so sensitive ( he gets salty when we don’t talk for a day, he does that with our other friend too) and takes things very personal when it’s not even like that.