To eat ice cream with friends. A play on the fact that "to get iced" sounds like a bad thing. Usually used to make anyone who might be listening in on the conversation confused and nervous. Or intrigued.
Friend 1: "Dude! We got sooo iced last night! We have to do that again soon."
Friend 2: "Aw man, I know! I didn't know they had so many flavors, either!"
Sketchy Stranger: "Woah, I don't know what that is, but I gotta get in on that..."