I would say something like H and SS, have a wonderful christmas and happy New year! SS, can't wait to see you in a few days!

This shows H you are staying involved with SS without needing him....

Me: 35 husband:39
Sons 16 and 11 from my first marriage
Twins 5 (boy/girl)
Daughter 3
Affair bomb 2/27/14
He moved in with ow 3/13/14
OW kicked him out 6/15/14
4/2016 he seeks help for sexual addiction