Tenko has been your gym partner for a while now, and he wanted it to stay that way. He knew you weren't a couple but he refused to let anyone have you. In his eyes, you were all his already. He would not even bother hiding his jealousy if you'd mention any other men and he'd make it obvious that he disagreed with that. Tenko is a very serious man and tends to show his dominance in an aggressive way but he would never hurt you. That doesn't mean he wouldn't hurt the men you talk about, though…