Amanda Seyfried Boyfriend Dominic Cooper's 'Too Relaxed' Attitude Confirmed To Be Cause Of Break Up; 'It Would Never Have Worked Long-Term,' Says 'Lovelace' Actress

While some 'Mamma Mia' fans were disheartened when Amanda Seyfried boyfriend Dominic Cooper turned out not to be 'The One' for the blonde beauty, the 28-year-old actress said that something was amiss with their relationship.

Amanda Seyfried and Dominic Cooper's break up took place in 2010 after more than three years of dating. For the 'Lovelace' actress, it's the differences in their character which took a toll on their love story.

"It would never have worked long-term. I'm too uptight for him. Or he's too relaxed for me," said the 'Mean Girls' star. Despite her split with Cooper, she doesn't have any trace of bitterness left. She claims that she will never be with someone who will be jealous of her friendship with Cooper.

"He'll always be in my life regardless of what his girlfriends or future wife think. I'm never going to be with a guy that can't deal with my friendship with him," she told ELLE magazine.

Aside from her tendency to become uptight, her anxiety and obsessive compulsive disorder (OCD) can likewise contribute to the challenges that she encounter whenever she's in a new relationship.

"I feel terrible for the younger me, because I thought I was crazy. Where was the fear coming from? It doesn't make any sense. It becomes physical - I would get dizzy and cry and the lights were too bright," said the 'Dear John' actress.

Even if many girls continue to admire her looks, Seyfried tells ELLE magazine that she is sometimes a victim of being self-conscious: "I don't have to look like a supermodel. I don't have to have those abs - the camera doesn't see that. But because we have all been designed to want these things, I'm a victim of this stuff, too."

Seyfried's current boyfriend is Justin Long whom she started dating in August 2013.