I'm happy to hear things have settled a bit. I'm gong to be brutally honest (and this is just my take), in regards to your h going on the trip, he will think and feel whatever it is he feels. I doubt a month away will make him realize what he has. I think the difficult thing when dealing with someone in MLC is that you can do all the work in the world and may have already been a spouse your h would be a fool to leave, and it simply doesn't register with the MLCer. If your h cannot deal with responsibilities, then he may not miss family life for quite some time. This is just my 2 cents.
Your h is on a long journey. Keep focusing on you and the kids. Yes, your M had flaws like every relationship. Work on making Sarah the absolute best Sarah possible and remind your children how much you love them.
Hang in there!
3 kids BD 12/15/13 (IDKIILY. ) Rope dropped Cirque du Soleil style D final 9-9-14 "Some people are born on 3rd base and go through life thinking they hit a triple." Barry Switzer
