Make plans for activities for you & the kids. If "DH" wants to come, he can. If not, he can drink, sunbathe, swim etc. Just get ready, say where you're going, come with or not.
By the pool, beach - put headphones in, iPod, podcasts, books. You can watch the kids, you don't have to listen too. At night, kids in bed, read them stories, a long shower and read in bed.
Treat it as a retreat. Give kids something to amuse them, then headphones in & relax.
Ask him "Would you like to..." wait for reply, then become occupied again. Keep it smooth, civil and polite.
Remember that children are watching and listening.
Smile, be civil, be the calm, happy parent.
But don't take any shit.
If that starts, leave the room taking kids with you, headphones in, head in book, go in pool, walk away. He can't argue with fresh air.
P.S. My parents kept up stony silences for days/weeks on end. Hostile, angry silences. Barbed comments, sly asides.Vile comments about each other.
I prayed they would divorce. How I prayed.