That's what happened when XP and I had our break at the beginning of the year... We hadn't had sex in almost a year but it was much easier when he wasn't living with me.
The thing is that you obviously have chemistry, and you can have a relationship with anyone you have chemistry with. The issue comes when you live with someone, you discover how compatible you are in the long term.
You also only see the "good" bits when you live apart. Me and XP got together again before he moved back in. It was great because when we saw each other we could give each other our full attention and leave everything else for when we were alone. The issue came when he moved back in and still expected 100% of my attention (minus that for DD of course) but the thing was that the washing and cooking and cleaning still needed doing, only before I was doing all of that when he left in the evening. I also didn't need his help as he wasn't living there/contributing to what needed doing! When he moved back he still expected every night to be date night.
Obviously we had a lot more issues than that, but for the benefit of your situation, I've simplified to show you that living together is very different to having chemistry.
I'm not going to judge you for sleeping with him don't have a leg to stand on on that front but if he's said that he won't move back in now, and you know logically (even if your emotions are fighting you) that it wouldn't work, then don't let him stop you from moving on.
Keep in mind that the odds are he's still going to strip clubs, pubs and clubs, etc on his down days. Of course, he won't tell you about it, but do you honestly think that since you two have broken up he hasn't slept with anyone else?
Of course there are still feelings there, and you don't need to be ashamed that you got caught up in them... I would just hate for you to end up in a situation where he has the upper hand and thinks he can do whatever he likes as you'd always have him back eventually.
Of course, it is your life, and your choices. But I have been in the position of letting them back in, and all I can say is unfortunately old habits do die hard.
P.S. Of course he said he wouldn't move back in. This way he gets to enjoy a relationship with you without getting called out on the crap he then goes and does once he leaves! But that's just me being cynical......