Guilt Complex

Is it that I'm a woman, a mother, or just compulsivity that I tend to feel guilty about things I shouldn't? Probably all of the above. Anyway, I have been invited to go this Saturday on a traveling bridal shower for a friend at work. It'll take all Saturday cuz we will catch the train in one town and ride it to Speyer (of the famed cathedral--a place and cathedral I've wanted to visit since high school AP Art History days...Holla, Beth!) So it'd be fun; a bunch of us girls wandering around, eating, drinking wine (surely), shopping, and chatting. A total girl-day. But I feel guilty because Radley would be taking the kids by himself to a BBQ we've been invited to that same day. Which would be fine for him. He always reports that his single-dad days are "easy, fine" (much to my infuriation...Is it too much for him to say, "Aw, it sucked! I don't know how you do it when I'm gone all the time! You're awesome--the best wife and mother ever!") Anyway, ugh. What is with this guilt?!?!