He's a serial adulterer, has been caught each time by YOU (as opposed to self-confessed), and even now, he's "ambivalent?" And you have NO KIDS?
Sorry, I know this is a pro-marriage site and all, but "SEE ya." Maybe maintain a legal separation (with you in your own home), and he can DATE you, and you can insist on NO-CONTACT and FULL-TRANSPARENCY, and if he can pull that off for 6-12 months, then MAYYYYYYBE.
But otherwise . . . unh-uh. Sorry. You're only setting yourself up for more heartache, and I don't see any true introspection, maturity or remorse on his part.
