Chris Brown and Rihanna - Valentine's Day is all about celebrating eternal love in a public way, but not all love stories make it to happily ever after. In entertainment, cheating is one of the most common reasons for marital drama. Here are a few celebrity affairs to remember.Breezy and RiRi's love affair went from It Couple to tragic tale in a matter of minutes following their 2009 domestic violence incident, but that was far from the end of their relationship. The former couple rekindled their romance in 2012 — while Chris was in the midst of his four-year relationship with Karrueche Tran. What's truly sad is how Kae found out her man was still hooking up with Rihanna: she saw pics of them at a Lakers game on Christmas Day while she was waiting for him at his condo.(Photo: Christopher Polk/Getty Images for NARAS)