My husband went on trips with his GF a couple of times. For me, the weird part was never the time that he was actually away - I LOVE being alone, and I looked at these trips as opportunities to spend time in our house all by myself. I also did make sure I had plenty of nice things to do, met up with friends, hosted a dinner for some people my husband is not too fond of,
stuff like that.
BUT. For me the moment he came home was always the most awkward and uncomfortable. I don't do well with those moments of shifting gear. And where does one begin to talk about the days that have passed? "how was it?"
So while I realize that this may be very specific to me as a person, my advice would be to really take time to 'get back together' after she gets home. Not let daily chores and responsibilities kick in immediately. Kind of like when you come home from a holiday, you need to ease back into your house and your life.. I always felt it took me some time to ease back into the connection with my husband. Also, ask all the questions you want, but be prepared that the answers may be uncomfortable. (Like when I asked him how many times they'd had sex. I kind of wished I'd never asked).
I guess that's what GG means by aftercare... I need a LOT of it, but what I need the most is for my husband to understand that I need time to readjust.