Emma Thompson, Helena Bonham Carter, and Sir Kenneth Branagh all have the “Harry Potter” films in common, but many people don’t realize that they have another, darker tie to one another. Now, Emma Thompson has opened up about the end of her marriage to Branagh, and how she has forgiven the woman who came between them.

Thompson and Branagh were considered the Golden Couple of British Hollywood in the ’90s and seemed to have it all; however, when Branagh met Helena Bonham Carter in 1994 while they were filming “Mary Shelley’s Frankenstein”, the two began an affair that would ultimately ruin his marriage. By 1995, he and Thompson had split, leaving him free to continue his relationship with Bonham Carter in the open. Nearly 20 years later, Thompson says she doesn’t have the energy to host negative feelings towards Bonham Carter.

“As Mike Nicholls [the film and theater director] once said, and I’ve picked it up because I think it’s such a wonderful phrase – all blood under the bridge. You can’t hold on to anything like that. I just think… pfft,” she told The Sunday Times. “It’s pointless. I haven’t got the energy for it. Helena and I made our peace years and years ago.”

These days, Thompson is happily married to actor/producer Greg Wise, but she says she does wonder about monogamy and believes it is an odd place for humans to find themselves in.

“I do sometimes wonder about whether there are alternatives, and about whether our fury and rage and disbelief and horror about infidelity is quite realistic,” she said. “I, of course, have got the T-shirt, so I understand the feelings very well, but I think as I get older and think about long-term relationships, I do see that they can change.”