He stabbed his girlfriend in the back so she would stop looking at her cell phone.

This girl’s boyfriend has had enough of her boyfriend looking at her cell phone all day long, taking pictures of himself and spectacularly ignoring him. When she ignores him, the guy buggers his girlfriend treacherously to see if she’ll wake the fuck up and start to pay attention to him. When he sticks it in her ass the slut makes a face of «fuck, that bastard has put it in my ass» and although you can see that it hurts the boyfriend ignores her and continues to sodomize her. This way it is long enough until he sees that the slut has already concentrated on the fuck, so he sticks it in even harder so that she learns.