Dominic Cooper thinks it will be ''odd'' to work with Amanda Seyfried on the 'Mamma Mia!' sequel.

The pair started dating after meeting on the set of the 2008 movie, in which their characters are engaged, and Dominic admitted that although they have remained friends, gazing into Amanda's eyes for 'Mamma Mia: Here We Go Again!' might be strange for him.

He told The Times' Weekend magazine: ''I think it will be fine working with Amanda again. I haven't spoken to her for a while, but we always remained friends. Though it'll be odd, gazing into each other's eyes and singing an Abba song.''

Amanda, 31, recently welcomed her first child with husband Thomas Sadoski, while Dominic, 39, has been dating actress Ruth Negga for seven years.

While Dominic enjoyed working on 'Mamma Mia', he admitted that period in his life was a ''very turbulent'' time, both personally and professionally.

He said: ''It was a very turbulent, but enjoyable, happy time and part of life. Everything! So to be going back there 10 years down the line, with the same group of people . . . It's like the point of reflection of 40: it will be a marker.''

Dominic currently works with Ruth on TV show 'Preacher' and the pair met when they were both cast in a production of 'Phèdre' in London in 2009.

He said: ''I met Ruth doing 'Phèdre'. She was brutally honest with me about my acting. Once she stopped halfway through rehearsal and said to [the director] Nick Hytner, 'Is he actually going to do it like that?' Then we continued to get lots of jobs together, completely coincidentally.''

Dominic also revealed that he would love to have children but believes he could be wary of marriage because of his parents' divorce.

When asked about children, he said: ''Yeah, yeah, yeah, absolutely. But it's a good and big decision, and one I want to be very much in the right head space to do. It's one of those things that this job doesn't always help you with, [always] being on the road.''

And speaking about marriage, he added: ''All that stuff probably has some effect, doesn't it? Marriage for a family is a very important, lovely, beautiful thing. But I also see people who make a choice not to do it, and I completely understand. Why does it have any impact on someone's love for someone? What does it mean?''