Mercy sex is sex, coital or oral, given a guy for comfort reasons rather than because of desire or love.
After Seamus had taken her to dinner Molly felt that she needed to give him some mercy sex.
by Heather Yamamoto January 28, 2006
It's what you pretty much end up with as a result of an ill fated "Fix Up Date"and the guy is just so pathetic cause of a divorce or some other normal catastrophe that any woman would toss back 2 Cosmos and move on..
" So i saw Brian a second time..and dang..it was so just draining to hear it over and over so i got to where mercy sex was either a placebo or anesthetic..the sex we won't even discuss....Hey!! Waiter more Cosmos here..!!
by MADELINEB February 08, 2008