Gently swatting Jace's hand away, Alec pretended to scowl but the expression turned to a smile instead. At least until he saw the change in expression and Jace was momentarily forgotten. "Sebastian, what..."

Slowly, he started reviewing what both of them had said that could have upset Sebastian. In case he wasn't around... Like Jack.

It wasn't what Alec had meant but he had the feeling that was what Sebastian was thinking. "Sebastian, everyone in the Library is immortal. We can't die. It's one of the reasons why I'm here instead of New York. I meant if I wasn't around because I was out patrolling or I was doing something else and you ran into something dangerous. I'm not planning on leaving you."