Although I like to mess with the dude, upsetting Tybalt is dangerous. The game is obviously set up to make you hate the dude and to mess with him. But the events during hell week, and also the fact that you *have* to date Jill, are also setting up Tybalt to hate the MC. The player's actions can only make it worse.
So why shouldn't you mess with Tybalt? Sage. He's going to get revenge, and the way to do it would probably involve Sage somehow. He's also obviously connected to Jill and Bella, so he also might do something involving them.