Got the same problem with my wife. Been married 13 years. Knew this was an issue from the start, but, hey, I love her.
It's been 15 years of sexual frustration for me; "Oh, I can't change, that's the way I am, hurry up" - but yet if I get my nut first, then "Oh, you came too quick, now what do I do, how come you had a premature ejaculation? You know I didn't come yet."
There's probably a lesson in there somewhere. Like, I'm so looking forward to being single again.