Strange relationship with my roommate

Hello,this is obviously a second account, for privacy reasons. Anyway, I have a few questions since I am confused about where I stand with my roommate and our relationship.We are of the same age, 24 and both male, and have been roommates for over a year now. We are great friends and do most things together, from drinking bears, watching tv, preparing meals etc etc. He has a serious GF (but no sex since they are both religious, even though from their talk she is more against it then him) and I do not at the moment. I would say I am maybe bi curios, but I am definitely into girls. He is definitely a straight and a twink, while I am just a average guy.Not really sure how it started out, but some months ago I have started touching him while we sit together or stuff like that. Basically I touch and feel most of his body. All of his torso, back, arms and legs. All of this only with my hands, while we are siting next to each other watching tv, talking or whatever. I also freely put my hands under his t-shirt to feel his nice flat stomach and twinky chest.He has never given any reaction to this, I have also asked him a few times if I am bothering him (while I was touching him) and he would always say it's OK. Several times I have tried to go close to his dick working slowly to it from his leg or stomach, and when I was only a few inches to it he would ask me to stop. Also if I touch his ass gently he would after some time ask me to stop. But with all the slow touching of the rest of his body he has no problem.We have talked about it a few times, mostly me asking if he was angry with me because of it and if it bothered him, but he would say that it doesn't rly bother him and that he's not angry.I always horny and hard while touching him, but I have never noticed him being hard during it. Also he never touches me nor tries to, and never invites me in any way to start touching him again. I just do it while next to him.So, wtf is this? We really are great friends, so maybe he's afraid to tell me to fuck off 'couse we might be worse of then? Maybe he doesn't view it as anything sensual at all, or maybe it really does not bother him that I am basic slithering all over his body?Or does he like it? I am at a total loss