Have you thought about not going home Friday after work and letting H fend for himself? If H is spending the day with OW, and plans to be home in time for you to get home from work, let him sit and wonder where you are for awhile. The longer the better.
Being a Friday night, can your S plan to spend the night at a friends house? Or maybe arrange to pick S up and go out to a movie.
On the flip side - if H isn't at OW's and you don't come home from work - is he going to miss you, or wish he HAD spent the day at OWs?
Based on H's reaction to you leaving, give him time to think about what he is truely giving up.
