What are we?

Wow, sounds like someone might be under-appreciated. You must put him through a lot of pain (can't assume you're to blame though). First figure out what you want. If you want to be his friends he's obviously a good guy. Try and make him understand what he's missing that you need and help him, give him a chance and let go of any resentment you might have for him. And if it still doesn't work out or you just aren't cut out to avoid breaking his heart like that then try to restrain yourself and give him time to get over you, but make sure he has someone to talk to about it in addition to you, someone who has been through the same thing and can relate. Trust me, I've been in his shoes and guys take it a lot harder than girls it seems. Complicated stuff like what you described will really end up ugly and hurtful. Most importantly, really try to think about him without thinking about yourself and make sure you are not taking him for granted.

He seems to still like you. Why did you break up if you can still be close friends?

Sounds like he still wants you.

I know exactly what you're going through. Same thing happened to me. Here's the thing. More than likely he still has feelings for you - after 3 1/2 years that's understandable. But if he doesn't want to get back together he is probably lonely and knows you will be there for him. You shouldn't let it keep going on like this. Sit down and talk to him. If getting back together is on the table, consider it. If it's not, tell him that the physical affection has to stop. It's not healthy to keep that kind of affection going on after a break-up because it's so confusing and can make people hang on to a relationship that they should move on from. I know it feels good to keep getting that attention but let him know that things will have to change unless he for sure wants you back and you want that too.