When a guy, traditionally with a big nose, puts his nose into a women's vagina until she orgasms. This usually involves some sort of nose plug and must be performed by someone who is able to hold their breathe for long periods of time.
Guy: Hey Guy 2 how'd it go with Sarah last night?
Guy 2: Oh it was great. She let me peacock her.
Guy: Dude that's Awesome! I wish I was you, but I don't have a big enough nose for peacocking, anyways.