Married young, happy, but wandering mind

I am happily married to my husband. We are coming up on two years married, been together for 8. I was 16 when we got together. He is the only person I've slept with and vice versa. We even have a great sex life and I feel crazy for even thinking about this - but suddenly I've been very sexual. I'm turned on all the time. I'm always down. I find lots of people attractive. I wonder what it's like to have sex with other people. Life specific people in my life. I feel bad about it. I know I would never do anything because I love my husband and I'm sexually satisfied by him, but I just think about sex a lot. Maybe I'm just not used to it but I feel bad.