I texted my girlfriend's roommate, and her girlfriend is breaking up! What should we do?

Just a birthday message, don't explain too much, just focus. Tell her you didn't get caught by him, and you don't feel sorry for anyone. He greeted your friend in your dormitory out of courtesy that day, and then told him that he wanted to know her better and know her better. Finally, he must emphasize that you have done nothing wrong to her. If she loves you, she will believe you.