A sex act involving 2 or more people where picnic style foods (apples, crackers, sandwiches, cheese, dip, etc.) are shoved into one participant's anus thus making him/her the "picnic basket". Everyone then proceeds to have sex, orgy style on top of a red-and-white checkerboard patterned blanket that has been laid under a tree on a grassy hill. After the group orgasm each person takes some food out of the aforementioned picnic basket to munch on.
*Note: 2 or more people need to be in attendance, sticking food up your ass and masturbating does not count.
"Jill and I were planning our own little Forbidden Picnic but on the way we met a homeless man which made our Picnic all the better."