Angst over watching the kids

This weekend the wife is having an all day scrapbooking party in our basement. So, I will be watching the kidlets, all 3, all day. They're fairly fun to spend time with but for some reason I get anxious about having to do it. I'm not sure why either. Until I'm actually spending the time with them it makes knots in my stomach.

I think it comes from feeling like I'm being deprived of "me time". But, I actually enjoy the time with the kids more than my "me time". Plus I get pleanty of "me time" every night after they go to sleep. The wife is very good about letting me do my thing from about 20:30'ish until snore time.

It must be something else that's got me fretting...