Excuse me you have a friend close enough to make you his best man and I haven't met him yet?

[Sirius is delighted, and he could be such an arse about this if he wanted to... but he doesn't. So he reins it in, but barely.]

It would be my pleasure! If I may negotiate two things in exchange? Firstly, I might need help affording nice clothes to wear. Secondly, I want to be your plus one to the wedding and party, obviously.