gain the upper hand
When you take control of a girl’s upper hand during a layabout, like on the couch, in bed, or at a party, and don’t let her go.
He grabbed her upper hand while they were watching TV. She tried to pull away, but he just squeezed harder.
She was on the couch, and he took her upper hand like it was a prize.
At the party, he wouldn’t let go of her upper hand. She called him a creep.