Drowning
After finishing his shower and putting on a new set of clothes from the bag dropped off by Ember, he headed out expecting a friendly family dinner.
Instead, he'd found Ember on the receiving end of an extremely fierce scolding from Diane. While the older woman was generally approving of Elric- and of Ember being in a good relationship, she was much less cool with Ember suddenly acting all rebellious.
Having your boyfriend over? Cool.
Inviting him to use your shower and then going in to possibly join him? Much less cool. Unlike Peliston who seemed cool with whatever they did in his house, Diane and Match had rules. Ember's scolding continued on for over ten minutes, and while Ember was getting it, Rothan pulled Elric out to the deck for a chat. He'd been close friends with Ember her entire life and was practically an older brother to her.
No brother would like the idea of a bad influence hanging around their sister.