If you're single or wishing you were on Valentine's Day, you are probably going to think about texting your ex. Just to catch up, see how they've been, and check whether they might have sex with you (or, if you're very lucky, to rub it in that you're having sex with someone better now). It's not always a good idea, but if you're going to do it, it's important you know what strategy to take based on your level of drunkenness and complete social isolation. So before you make any bad decisions this Valentine's, make sure you're making those bad decisions right.