The 31-year-old appeared on The Tonight Show Starring Jimmy Fallon to chat about her new film Rebecca.
She had cancelled all interviews after the photos of herself and Dominic enjoying a romantic getaway surfaced last week but it seems she must have agreed to appear on Jimmy Fallon's show only if no mention of the scandal was mentioned.
The star appeared nervous at the beginning of the chat, but became more animated while talking about rumours of a third Mamma Mia movie, saying she'd jump at the chance to play the younger version of Meryl Streep's Donna Sheridan again.
Speaking of her audition for the film, Lily revealed she was "desperate" to be cast in the sequel, but the audition was during Glastonbury, so she was nervous her voice would be horrible after five days of "screaming".
"I auditioned for Mamma Mia! during Glastonbury weekend. I knew I had to sing in this audition, I was desperate for this part," she said.
"It was due to be scheduled at the end of Glastonbury. I knew for sure that after screaming in a field for five days there was no way I would be able to sing, so I did it on the way in the car.
"I had the car parked and filled to the brim with wellies. I went to Glasto. My phone ran out of battery.
"It wasn’t until on the way home, I plugged my phone in and my agent called me. I was like, [raspy voice] … ‘Hello!’
"She said, ‘You got the job!’ I said, ‘Please say it doesn’t start soon’."
Jimmy asked Lily if she would be keen to do a third Mamma Mia film to which she quickly responded, "Yes, I would do 4,5,6,7,8,9,10. I’m down. Signed, sealed, delivered, I’m theirs."
Lily and Dominic made headlines last week after being photographed on a very romantic trip to Rome, despite the fact Dominic and his wife Catherine Fitzgerald have since told reporters they are "very much still together".
Dominic removed his wedding ring for the getaway with he and Lily seemingly unable to keep their hands off each other.
Daily Mail reports just hours after Catherine told friends she was "heartbroken" over the images of her husband kissing his Pursuit of Love co-star, she agreed to put on a bizarre show of unity in front of photographers who waited outside their home.
The publication reports that Catherine appeared to be anxious about the public display and even held a tissue and hid her ring finger in her pocket.
The pair handed the waiting reporters a note saying, "Our marriage is strong and we're very much still together."
A friend told the Daily Mail: "Catherine has been trying to speak with Dominic but he's not answering his phone. She's totally shocked because she didn't know anything was going on. They were very much together, so this is completely out of the blue.
"She thought they had a good marriage and now it's probably over. That's how she feels right now but the two of them need to speak but at the moment, she's lost for words."