I hate to be the bearer of bad news, but it isn't going to work. Sex isn't a super important factor, unless it's in a case like this. You broke up with him to go have promiscuous sex, realized you wanted the relationship part back so went back to him (and why he accepted you back is beyond me), and now the pattern is starting to repeat itself. You feel guilty, but this won't stop you wanting sex. You'll want promiscuousness because you have the need still, but you don't feel sexually attracted to him, and why should you? You already left him for somebody better in bed.
I'm not a b***h whatsoever, but you need some tough love.
At this point, you either break it off and continue being the wild, untamed monster that nobody wants to have a relationship with because they're scared of you running off, or you realize sex isn't important in order to love someone with complete acceptance, and you focus on the IMPORTANT parts of a relationship.
Best of luck.