Ashton's Alleged Mistress I Didn't Torpedo His Marriage!

11/24/2011 10:08 AM PST

Ashton Kutcher's Alleged Mistress Sara Leal: I Didn't Torpedo His Marriage to Demi Moore!

Sara Leal -- the 22-year-old blonde who allegedly slept with Ashton Kutcher this summer -- insists she isn't responsible for the actor's crumbling marriage to Demi Moore ... telling TMZ, she was just a "bump in the road."

Sara tells us, Ashton and Demi were having problems long before she came along -- but was she the straw that broke the camel's back?