When you slip your dick into a fat chick (boinking her) who isn't expecting it, causing her to involuntarily let out a little "oink". She must be fat. And she must be sweaty. This is similar to when a chick involuntarily "oinks" while laughing.
That fat broad Betty totally let out a Boink Oink when I was porking her last night. Bless her heart.
by Party Crashers October 11, 2009