scara wasn't at home because he told you that he'll go to his 'guy friend' so you agreed and let him go out.

He got an idea and planned to make you jealous. So he called you by showing mona on the bed with him. You got angry a little but didn't show it. And when you turned around he saw Childe on your back chilling.

"I'LL PUNCH YOU IF YOU DARE LAID YOUR DIRTY HAND ON MY GIRLFRIEND!" he said angrily as he quickly grabbed his bag to go home.