A euphemism for sexual intercourse,
presumably derived from the fact that
Gatsby lived in a place called "
West Egg." The resulting euphemism implies that the sex is intended to result in pregnancy.
Matt- "Dude, when I go
abroad next year I'm gonna be 'sending
Gatsby back home' all night, every night!"
Dave- "Matt, the last thing we need is a whole
shit ton of pregnant furries."