Breaking news! According to the Ivory Tower, "all the most inane, minimally-researched studies get the maximum media exposure" wing, there are 237 reaons humans have sex that pretty much all boil down to "why not?" Shockingly, they're somewhat redundant: "I had no self control" and "It was a romantic setting" are just different ways of saying "I was drunk," in our experience, and "The person's physical appearance turned me on" and "The person had a desirable body" could, depending on the level of alcohol imbibed, mean the same thing as "I was slumming." And yeah we're taking New York Times resident sexologist John Tierney's bait and adding our own, most of which boil down to "I am poor," if not quite as poor as Tierney's fourth commenter, who suggests "So I could bum a cigarette afterwards." Classy!

• The um, news? Was somehow inspiring?
  
• You were locked out of the house.
  
• The person really needed to get laid and you like to think of yourself as a Good Samaritan. (Sexaritan?)
  
• To avoid being groped by someone even uglier after the inevitable loss of consciousness on the subway ride home.
  
• Because you were feeling fat, but he was actually fat, thereby making you feel small, and in any case ridding you of some much-maligned water weight.
  
• He played "Range Life" on the jukebox.
  
• You'd had good luck with that astrological sign before.

• You'd never fucked someone of that ethnic origin before.
• Because you had a close girlfriend who'd fucked him once and if you're not the type of girl to gay out on your girlfriends, being a degree of sexaration from them is almost as much of a bonding experience as, like, sharing breast milk. More if you think about how much easier it is to expose yourself to each other's diseases with the help of a dude!
• They had achieved a somewhat absurd, ideally niche and/or D-list brand of fame and it was a good story.
• Like, for instance, Steve Aoki.
• Um, the Starr report had just come out and it dawned on you that you were pathetic.
• The surliest guy at the office became decidedly less surly at happy hour.
• The person played the Dead Milkmen on the jukebox.
• The masturbation is maybe giving you carpal tunnel?

Okay, now have fun and add your own, etc. etc.