How did you "notice" he was at some festival? Snooping? Sounds like anti-detaching. That's part of why you caved and pursued, asking him what he is doing. Yes he is out without you. You should be doing that too.
H 34 W 29 BD 3/12/18 Divorce Busted Spring 19
It is not things that bother us, but the stories we tell ourselves about things.