Can be synonmus with "sausage fest" or "sausage party"
Don't ever go to parties at Katie's house.
She always has massive amounts of dudes over so her fat ass has a chance to get laid. She needs the dick picnic to have an snowball's chance in hell.
A get together where there are many penises.
A get together where penises are enjoyed.
A collection of people who would generally be described by people who know them as dicks or assholes.
Man I hate those guys over there, it's a real dickpicnic.