Humiliating the Sissy

My wife was already mad at me for never being good enough at sex, and then she caught me trying on her red leather skirt.
I was ashamed and embarrassed, but she didn't judge me. Instead, she offered me a deal. I can wear all her clothes, but she's free to invite her handsome, muscular black friend to our bedroom.
There's only one catch and it's not negotiable; I must wear a skirt in front of him.