I Raise! Why?

[Tryptamean]

live table. You are the only white dude, all others are asian. Gambool is in full effect. You are card dead and getting your ass handed to you in general, but having a good time at a fun, excellent table. You actually pick up a big hand and announce, "I raise!". Without missing a beat, one other dude immediately asks, "Why?"

What is the most +ev thing to say in response? Does it matter? If it doesn't matter, what is the funniest thing to say?