If you're nursing, you might have to leave the house (the little darlings have noses like bloodhounds and can smell Mommy if she's within a mile, I swear!), and it is going to suck to be Daddy for a few days, 'cause baby is not going to like Mommy being gone at bedtime, but that was the only way I was able to get my oldest to let somebody else put him to bed.
My youngest will go to sleep for his Daddy, because they have a totally different ritual than we do when I put him to sleep. I wrap him up and nurse him to sleep and then put him in his crib. His Dad wraps him up and walks and dances and sings to him until he's asleep. (He's been a total failure at breast-feeding for some reason! Giggle!)
If you leave them be, no matter how hard it is, they'll probably work it out between the two of them. It's hard when they're crying (and you know that they just want you) to butt out, I know, but I'm sure your husband can handle it if you let him.
Of course, it's possible that exactly nothing you work out between the three of you will work with a babysitter, I've been for exactly one (aborted) romantic dinner since my daughter was born. But, I have been for a number of wonderfull romantic lunches. My teenagers will stay with their little sister and brother during the day, but after the last time, there is no way in the world they will stay with them anytime anywhere near bedtime. And they've polluted the babysitter pool, all of their friends have heard the story of "When the baby screamed for Mom for an hour straight," and they won't babysit either. Knowing an entire high-school of teenagers who could babysit for you, but won't, is a bloody greek tragedy.