If you sit down, get quiet, and think about it, can you honestly see a time in your future together when you won't have to worry about him being attracted to his groupies, or about him doing any drug, or him doing his usual sort of hurtful self-serving behaviors? Can you see him being 100% honest, no exceptions, and only interested in you & the kids, willing to turn his back on exciting things (like adoring 15 year olds) forever?
If you can't see any of this happening, booklover, then there's an answer there for you. You have to decide if that's what you signed up for.
If you can't see this happening and you still want to stay, then there's another, and you have to ask yourself why you think this is the best you are allowed to expect out of life.
And if you CAN see this happening -- after all, you of all people have seen what turns his crank in life -- and it doesn't feel like a pollyanna fantasy, then there's another answer. Is the possible pain going to be outweighed by the joy and support he gives you in years to come? It might. Only you know if it's a fair gamble for you.
It's all about you. You have the answers in your own hands. You just have to have the courage to follow through, whichever way that leads you.
But you knew all that
Hugs and strength,
GiveLove