Ryan Casey reveals Hollywood sexcapades in 'But You Like Really Dated?'

Can't keep track of Taylor Swift's love life or which ex is the subject of her latest song? Have you lost count remembering how many times Elizabeth Taylor was married? Then you need to check out Ryan Casey's hilarious celebs and sexcapades book, "But You Like Really Dated?" (HarperCollins), the ultimate source for looking up who's been hooking up in Hollywood.

Here's a fourplay of what's between the covers.