Kelly Preston and George Clooney: If it weren't for dating Kelly Preston, George would have never had his beloved pet potbellied pig, Max. The hog was originally a gift for Preston, who was George's live-in girlfriend in the late '80s. When the couple of two years broke up in 1989, George retained custody of Max.
Corey Haim and Alyssa Milano: According to the laws of Hollywood, Alyssa and Corey were bound to have dated in the '80s: They were both teen stars, and they were both hot. Alyssa and Corey didn't just have a fling either -- they dated for three years. That's, like, the equivalent of marriage in young Hollywood. When Corey died of pneumonia in 2010, Alyssa tweeted, "Just woke up to the sad, sad news that Corey Haim passed away. RIP sweet boy."