I think he's upset that I wouldn't tell him why I am taking a trip this weekend, so now he's being nasty.
And that's why you don't reply. That only leads to trouble.
At worst, if he gets nasty in person, point out that jealousy isn't very attractive and walk awway.
Me: 44, Wife: 39 M: 17 years T: 20 years Bomb on 08/25/09 1/13/10: MC started 1/28/10, 2/8/10: More bombs 8/28/10: Wife moved out No talk of D, no movement