Angelic Wife

Looking at my wife, you would automatically think librarian. Plain Jane and a little on the small size.
Don't let those ordinary looks fool you. She is in fact a library employee, but a library of antiquities.
However my wife is a total slut and I for one cannot match her sexual appetite.
She's five feet three, slim, large breasted and has long curling brunette hair. She wears glasses and dresses ordinarily for work.
Since we've been married, which is now four years, she's had sex with eighteen different men I know of. And five of those have been her senior colleagues.
This past year, she and I have only had sex one on one, five times. The rest of the time she has one of her lovers around fucking her.
I either join in, I watch and masturbate. Or if she desires it, she instructs and watches me being fucked.
Its something I never thought would appeal to me, gay sex. Yet each time she has me fucked, I'm enjoying it more and more.
But the main thing is, I get to be involved with my beautiful wife sexually, and I just love watching her being fucked.