yes, and

yes, and (uncountable)

1. (theater) A rule of improvisation whereby one performer should accept another's statement and build on it.

yes, and (...)?

1. Diminishes a speaker's confession of the listener's accusation.

• Used in informal speech, chiefly by Americans.
• Used when conceding an accusation to be true, but questioning or rejecting the relevance or importance thereof.
• Used especially in disregard of likely controversy amongst one's peers as a result of the accusation being true.
• The prosody is very important. There must be an audible pause between the two words, and they may be written as two full sentences, or interspersed with ellipses, to guide a reader:

Amber: You're telling me you put pineapple on your pizza?
Naomi: Yes. And ...?

• so, what?; yes, and what of it?; okay, but what's your point?; who cares?; okay, and?