tomsteve

fell in love with him or an illusion you had?
did you tell him you fell in love then he drank again?
he didnt have a slip- slips are falling back into an old thought or behavior without drinking.
he drank.

"Meaning, we still see each other, still have sex and still stay exclusive but without the "bf/gf" title."
in other words, use you for his own benefit.

"or should I see it as a loving gesture that he isn't letting me go? '

its an unloving gesture towards yourself if you dont walk away.
he's unavailable mentally and emotionally.
you dont deserve to be used to in a relationship with a selfish, self centered, lieing egomaniac

keep going back to al anon. get their literature. listen. if you mentioned why you are there, they may have offered their expeirence and what they had to do without straight up telling you what to do.
but REMEMBER
al anon isnt about the alcoholic- its about YOU.

one more thing:
" Leaving him is not an option for me if we are both willing to work through this"
you could be in for a whole lot of gloom,dispair, and agony as HIS idea or "working through this " and yours arent the same