A Slip of the thumb
A thumb slip is when you're trying to pleasure your girl, but your thumb goes in her butt instead of her vagina because you're too clueless.
I was trying to make out with my girl, but my thumb went in her butt. She laughed and said, ‘You’re the worst.’
I was trying to pleasure my girl, but my thumb slipped in her butt. She just looked at me like I was a total loser.
I tried to be romantic, but my thumb went in her butt. She said, ‘You’re not romantic. You’re just dumb.’