Why do I feel guilty about going out?

So here's the story: I've been very happily married for the past 7 years & my husband & I have a wonderful relationship. We have 2 kids, 5 & 4months old & they are both really good kids. I've never really had close friends that I would spend a lot of time with since we were married, however, that changed when my son started school last year. I made a lot of friends & now have a best friend whom my husband thinks is terrific. Normally, I do things with my best friend during the day once or twice a week when the kids are in school & occasionally we'll go shopping in the evenings. My husband has no problems at all with this & like's watching the kids. Anyways, a group of us have started making a regular point of having a mommy night out about once a month or every 2 months on a Friday night. Keep in mind, these are all married mature women with kids & we go out for dinner, desserts or sometime's a movie. We are not into the bar/club scene anymore. Anyways, I feel like my husband is jealous when I go out & he made a comment recently how married couples should go out together instead of alone! I thought this was ridiculous & I feel like he's insecure. I have been 100% faithful & never given him any reason to feel insecure, I don't have guy friends or anything like that. He doesn't have many friends outside of work that he hangs out with, except for one & he goes to his house about once a month to watch UFC. I want him to have friends & go out because I don't think it's healthy. Well, what do you think?