A party in which the guys “conveniently” forget to wear pants.

As first mentioned in a classic episode of Billups and McBride.
McBride: "Chet, you know what we should do?"
Billups: "What's that Gabe?"
McBride: "We should throw a half and half party."
Billups: "A half and half party? What's that?"
McBride: "Well, we get some kegs and then the guys show up first and we all start drinking. Then when the ladies show up, we say 'Would you feel more comfortable if we put our pants on?"
by AGC via CH January 8, 2010
Get the Half and Half Party mug.