The voice in the back of his head telling him this may not be the smartest idea doesn't completely go away, but he does a pretty good job suppressing it. Because this feels good, maybe not quite right but it's not wrong, either, and he's so, so sick of feeling wrong.
When he's with Sebastian, he isn't thinking about Blaine. Not about Blaine, not about his failure as a husband or his failure as a father, and really that's all he wants, is to not be plagued by it all, by the hurt and the self-loathing that follows him. And Sebastian is a really, really good distraction.
He feels guilty about it, in the back of his mind – he tries not to think about what Blaine would think, but it's there sometimes, in the moments in between, when he's alone in his bed in the small apartment he found for himself, wondering how the hell he'd gotten here and where the hell he's going and what the fuck he's doing. But then he's with Sebastian again and he lets himself forget and it's alright, Sebastian kisses him and touches him and suddenly everything else in the world fades into the background.
He doesn't really know what it is that they're doing. They're not boyfriends, definitely not, but they're not– "friends" isn't right, either. They're not even friends with benefits, not really, from the outside it might look that way but that's not how it feels, not really.
Probably best not to label it anyway. If he labels it then it's real, and if it's real, well…
Well.
He's not sure what that would mean.
What it would mean for him.
What it would mean for them. For Kurt and Sebastian, and for Kurt and Blaine.
And he's not sure which he's more worried about.