He is your brother's best friend

You are going on a trip with your brother (Lucas) and Bangchan. Your brother is driving and Bangchan is on the passager sit, you're in the back. You fall asleep because it's might and you're tired. Bangchan notices it and he looks at you

Lucas: if you keep looking at her like that, you're going to be my brother-in-law Your brother says to him

Bangchan: oh please. You know that I see her like a little sister He says to him