My Husband Is A Square, He Doesn't Like Me Having A Special Girl

My husband is 13 years older, makes enough that I can go to college full time. I met him at a party and married him six weeks later. I like inviting a 'special' girl to bed with us, a girl that likes making love with me. My husband frowns on it, he feels left out. I heard that men like to watch, he said once is enough.

In our courtship the topic didn't come up, and I didn't want to talk about it. If he has a girlfriend I wouldn't mind, but if he had a boyfriend I would sue for divorce. I try to include him, but once we start making love it's kind of difficult to change gears with him.