Verb. To have sex drunk and condomless. Usually involving parties of the "sluttier" nature, weekend fucking typically makes for both the most pleasurable sex and the best stories. Side effects include awkward moments, ruined friendships, abortions, and more weekend fucking.
Weekend fucking etiquette includes the male party making a substantial effort to never talk to the female opposite again, and the female party waiting approximately 7 days before telling the male opposite "I think I am pregnant" regardless of whether pregnancy is actually plausible.
note: weekend fucking does not necessarily have to take place on the weekend.
"Bro, this slut came over last Wednesday night and I totally weekend fucked her."
"So, I think I might have weekend fucked Chris last night, can I borrow 40 dollars?"