It was cruel to ask you out and start dating you as a dare, but his ego was too big to risk looking like a "chicken".

It was supposed to be simple. Ask you out, date you for a week, humiliate you.

A date turned into many, and a week turned into a month.

The forced proximity between you two had resulted in him actually getting to know you, and now he was hooked.

He let the dare go, almost forgetting about it, until someone sent you screenshots from when Satoru when the dare started.