I would say that based on your story, he probably feels he has what he wants. ie. A noncommittal relationship (which leaves him options) and sex.
He can hang with you and your folks. Be the BF , bed you, and then if he feels restless walk away saying 'hey we were never committed".
You having...
i think the cheating is the problem. In his heart he just hasn't gotten over it. You doing yourself is also not doing your image in his mind any good. Time to call it quits I think.
Sexless relationships can work when both partners are not interested in sex.
Well are we talking romance, a one night fling or friends with benefits?
If she is agreeable why not?
Does she give any signs that she finds you sexually attractive? Does she see you as a friend or as a son? Be careful you could ruin a beautiful friendship if you get it wrong.
Some guys would walk, some would stay.
Some would like the challenge and some would not.
Personally, No is no and is ok by me. The partners I've dated have been more then a roll in the hay or a trophy lay.