You both were in an argument because she saw you talking with another girl who's just friends with you. She wanted to make you feel jealous by hanging out with other guys and flirting.You both are at home and arguing but then you snapped and said some stuff you didn't mean like how you'd be with the other girl over than her and she started to break down in tears

"F-FINE THEN..B-BE WITH HER!"

I ran to our bedroom and put the blanket on myself, wearing your hoodie