Anna Kendrick has recalled confronting her cheating ex-boyfriend and the other woman.
The 37-year-old actress - who didn't name her former flame - has opened up on her reaction after finding a year-long text exchange which proved her long term partner had been faithful.
Appearing on Dax Shepard's 'Armchair Expert' podcast, she said: "I ended up finding out some capital T truth and was exposed to year-long text exchange and went, 'Oh, I was right about everything. Oh, OK'. It was actually way worse than I even thought."
Once she discovered the messages, Anna reflected on a previous conversation she and her ex had during couple's therapy as he angrily denied being interested in the woman in question.
She recalled: "He is screaming at me, 'It was passing crush, you're so insecure, I never saw a relationship with this girl, I even told my best friend I never saw a relationship with this girl.' "
However, the texts gave the 'Pitch Perfect' star some clarity.
She claimed in one message her ex told the woman: "After a week of f****** you, I want to blow up my life for you. Just say the word and we'll ride off into the sunset together."
She added: "When I confronted him on it, he said, 'I don't know what you're talking about.' Which, again, was kind of a relief, because you go - 'Oh, you're pathological. This is in black and white.' "
She also sent an email to the woman to explain that she knew about the situation and didn't blame her for what had happened.
She told her: "''I don't put this at your doorstep. You made a mistake, but you're 25. We've all done stupid s***. I very much lay this at his doorstep.
"'I just wanted you to know that. I don't know why we would ever be in a room together, but if we were I just kind of need you to know. If I were you I wouldn't want to talk to me, but if you ever wanted to talk I'm more than willing.' "
To the woman's "eternal credit", she asked if she could call Anna and they spoke on the phone "for about an hour", with the woman saying she was "so embarrassed" as she apologised for the "mistake", which gave the star some closure and clarity.
Anna said: "I hadn't eaten in a week. I couldn't sleep. I couldn't eat. I had this conversation with this girl and we hung up and I was like, 'Oh, I need a plate of nachos'.
"My whole body just went, 'You can grieve. You're not crazy. You're safe. You can grieve. You can eat nachos. You can have a glass of wine'...
"It was like my whole body got whatever it needed. It at least stopped that total panicked state that I'd kind of been in for a year."