Whatever you do on Valentine's Day — whether you spend your entire last paycheque on a meal at a fancy restaurant or just nuke some Bagel Bites in the microwave and catch up on The Bachelor , — if you're with a partner, odds are good your night will end with sex. One 2017 study found that 59% of people in relationships plan to have sex on Valentine’s Day — and so do 16% of singles, who may have scheduled a first date for the occasion.