1 definition by SixtyBucks
A sexual activity between three people, including at least two women, in which the third person is lying down on his back between two women who are kneeling up and supporting each other, while the person lying down uses his thumbs to massage the insides of the women's vaginal walls, thus causing both his thumbs to be in the upright position.
"Suzie, Betty, and I had a great time last night. I gave them two thumbs up while they were making out."
by SixtyBucks October 9, 2013