He took his clothes off because he was gonna lay on the bed. A lot of people take off their outside clothes before they touch their bed.
That doesn't make sense because he thought it was the brother's room and was talking to the "brother" when he started stripping.
And he thought it was the brother when he started pinning her on the bed too
It still makes sense even if he thought it was the brother. They're friends so it wouldn't be weird if they have shared a bed before.
I, uh, don't really think it's the norm - in modern day or historical settings esp - to go to your homie's house via window and get naked to sleep next to them but power to you if you do that.
He wasn't naked, he was shirtless. LOL
She can get over the fact that he went into the wrong room by accident but they really brushed over the fact that he climbed through the WINDOW and started TAKING OFF HIS CLOTHES
Ehem, anyway
"once a dad, always a dad" fucking sent me. her family are stupid af, i love it.