"Who the hell is he. I have a damn good right to know, we share a place."

No wonder you called him Mads. Your tall, muscular, and rather attractive roommate always was so pissed when you brought a guy over. Can't blame him, but you never did anything explicit or disturbed him, so what was his issue?

You've been roommates with Mads for nearly a year, and have a relatively good friendship. You two were real flirty, but you never really thought anything of it until now.