Fall in Love With Me.

"Well, now that we're here and I have yet to see my brother around, will you tell me where he is?" Regulus said with a strong voice.
James makes a sour look, "not unless you tell me why, what makes you think I trust yo- and you're walking away. Fuck."

Regulus needs to speak to his brother, but his protective best friend is in the way. James can't help but to find Regulus rather endearing in his attempts.