For the guys here... Just imagine paying child support for kids that aren't even yours.  One guy did it... found out the kids weren't his and now he is awarded $40k from his ex.  Click here for story.  Side Note: I can understand the guy being extremely upset knowing the kids aren't his... but at the end of the day... after you raise kids... they're still yours right?  It takes a father to be a sperm donor but a dad to take care and love kids.