My marriage has survived the "divorce talk" twice. We have been married for 15 years, together for 16.
However you say some things here that would indicate that maybe the talk needs to become reality.
We first had the talk when I caught him cheating. He said he wanted out so I said fine. In the end it wasn't what he wanted he was just so sure I would leave him, he wanted to be the leaver, not the leavee.
We had the talk again after he acted like a total imbecile on our vacation, actually throwing a tantrum that it was too cold in the hotel room (air on low and about 100 degrees out). When I refused to turn it off he went nuts. We drove over 15 hours to get to our vacation spot and came home 1.5 days later because I refused to stay there with him after that. He said we were not compatible and wanted a divorce so I filed, and it took a bit but he finally admitted that wasn't what he wanted and we worked through it.
Couple key things...you should not have to beg for intimacy. Try something new maybe, like lingerie or romantic dinner but if he isn't interested, in you chances are dressing it up won't work, and just make you feel bad. You can't control his comings and goings, he is an adult, and clearly feels that he doesn't owe you anything, not even respect. He is probably actively cheating, and more than likely carrying on a relationship.
My suggestion, kick him out, or take the kids and leave. File for a separation. Distance can make the heart grow fonder, he will either have some time to himself and realize he wants to be with you, or he will tell you that he wants divorce. What would be better still is for you to move out, with the kids, and have some time for yourself and you realize you don't want a relationship like that and you say you want a divorce.
Good luck.