Your thoughts/advice please?

Met a guy 4 yrs ago (hes now 30, i'm 33). First he was really shy, went red when i spoke etc, got easier after a few months. Eventually he offered to help me with something then we changed no's and I took him out as a thankyou. We keep in touch, got out some more, get quite close at one point then he goes distant. Speaks if i do but no more than that, few months later he gets in touch we get chatting and hanging out again, then he goes distant again. So after a while i get in touch with him to see if he'd do me a favour, he does, we go out again a couple times, get to making out then he goes distant again. So over the past few months we get close again, get to sleeping together, first time i initiated it, the other times it was him, so he's done his distant thing again, he'll always reply to my texts, seems ok, tells me what he's been doing, calls me 'sxy' and asks how i am etc, but once again he's stopped initiating contact.
What do you think of this. I'm 99% sure he's not going distant because of another girl, he is really shy, not much girl experience, i dont think there was any before me! He still lives at home with mum and dad, is an only child and a bit of a loner, his hobbies are all things he can do on his own.
This has been going on years and i like him an awful lot and i know he likes me too.
Any answers as to why he keeps backing off. In the past 2 months i've not seen him, he has always replied to my texts though, and apologises for not replying right away etc, still i get the 'sxy' thing. Whats going on?

The last time i saw him he gave me a big hug and kiss as he left, he's not normally a hugging type.

His pattern was to always distance himself from you so it was a natural progression that he would distance himself after sex as well.

Tell me, why didn't you ask him if he would be distancing himself from you after you had sex with him? Why didn't you protect your own best interests and instead ask this question of strangers on a forum board rather than him?

He's only interested in a casual relationship with you, doesn't want the hinderences and responsibilities or having to answer to your expectations ... but he will, like anyone I suppose, take what you offered so readily.

Seems so, anyway.

I know someone that is just like him. He is in his early 40s, still living with his parents and his social time is at the local pub......that's his life. Apparently his gets sex whenever it's offered and that's as far as it goes, he never dates. There have been times we just tell him if he is gay we will still love him just the same, but I guess we will never know for sure. His parents have asked us to get him to move out and we have given him the talk many times. I think it's fear of responsibility, change, being alone and a touch of immaturity. I guess there are those that prefer to keep things simple and have a life of solitude.