First, it is not good modelling for your kids to see you desperately clinging to a guy who doesn't love you. Stop it.
Second - no, your kids do not need to be involved in your dating. really, they shouldn't meet a guy you are dating until you've been seeing him at least 6 months to a year and are POSITIVE that it is going to be a long-term relationship. But that doesn't mean you can't date - just keep it out of the kids' world. Your exBF has no grounds to complain if you are dating but the kids never meet your dates. Whether you choose to have sex or not is your decision - there are guys out there who would respect your decision.
Third - it's because you are still not over your divorce, that you need to so desperately make this work. You can't admit to yourself that you made a mistake - and somehow, if you can get this guy to pretend to be in a relationship with you, then you can fool yourself into thinking things are okay. Face up to the facts - he's not in love with you, he's a reasonably ok co-parent (according to you) - ok. Quit trying to make it something it isn't, and go find a nice man to date who can give you some of the affection and affirmation you so desperately crave.
