A friend!? [A very close one at that.] No way! With her it was always: [His voice raises an octave to sound more "feminine" with a hint of a whine and a shrill added on for extra effect.] Mr. Vash!! Where do you think you're going this time!?

Or.

Mr.Vash! Just what do you think you're doing?

Or.

Vash! Stop that this instant!

Or.

Vash! I'm a mean, bossy stalker who isn't going to let you have any fun what-so-ever for the rest of your life!

[So, he might have just made that last one up.]