Just to rephrase so you understand the gravity of the situation, you've frequently made the choice to break the unspoken agreement of fidelity with people you're in an exclusive relationship with. If you can't accept the terms of the relationship, why lead your boyfriends on into thinking you do and cause them years of hurt by breaking their trust?

Everybody feels tempted sometimes in relationships. It's probably not a popular opinion, but longing for the greener grasses is perfectly human and natural. However when you love your partner, you choose to respect the terms of the relationship and it's easiest to reduce temptation by distancing yourself from the people who tempt you. Sometimes completely cutting contact with them might be necessary. So far you've been doing the opposite, and you find yourself constantly sexually pursuing your male friends. What do you think you're missing that's causing you to behave like this, surely there's a reason?

Would it be a fair assessment to say that you like having male friendships exactly because they give you that thrill of the chase and because you enjoy the flirting and the sexual tension when you're with them?

Why not just do open relationships only then? Have you looked into polyamory? Just please, for the sake of your partners, whatever you do, don't enter another 'monogamous' relationship again until you figure it out.