In The Movie "Conversations Of Other Women" Is The Man The Womens Ex Husband?

I really liked tihs movie, but its kind of confusing. Is the man (Aeron Ekhart) the womens (Helena Bonham Carter)ex husband? At the beginning she says that the people at the wedding are her ex husbands friends. And turns out she and the man have a past. Is he her ex husband? or just one of her old boyfriends?