Ummmm....not that Bill Shatner would not have credibility on the topic, but the song with the lyrics "why don't we just get drunk and screw" was written and first performed by Jimmy Buffet, in my recollection and a Wikipedia listing.

From Wikipedia (accessed same time as this post)
"Why Don't We Get Drunk (and Screw)" is a novelty song written and performed by American popular music singer-songwriter Jimmy Buffett. It was a b-side to the first single ("The Great Filling Station Holdup") from his 1973 album A White Sport Coat and a Pink Crustacean.
Buffett wrote the song under the pseudonym Marvin Gardens,