To place ones testicle or testicles inside the anus or vagina of his sexual partner. Similar terms include "bathing the dog" "the vagina fly trap". Variations include the "lego lock"; where one places one testicle in the rectum while simualtainiously placing the other free testicle in the vagina. Or the "bubble bath" where the both testicles are placed into the vagina or ass and queefed or farted on.
My wafe skills have suffered ever since the cancer has spread to my groin.