[Seb's heart sinks. He hears that "but" loud and clear.]

You don't have to - to change anything for me. I'm not gonna insist you leave her or make anything official with me, I swear. I won't get in the way of your life. I can be your secret.

[Ugh, what is this side of him? His own words make his stomach turn but he can't seem to stem the tide.]

Please.