The actor, who plays Draco Malfoy in the wizarding series, told MTV News that Jade Olivia will play his character's wife in the final moments of Harry Potter And The Deathly Hallows.
"The producers actually came to me about six months ago and asked me. I was a bit like, 'OK, I'll ask her'. She was slightly reluctant, but I pulled her arm and twisted it," he explained.
"She was filming with me for three days at Kings Cross. Very excited. She plays my wife. We had a kid together. It was all very rush, rush. We were married for three days. It was all very fun."
Felton picked up the 'Best Villain' gong for his work in Harry Potter And The Half-Blood Prince at the MTV Movie Awards in Los Angeles over the weekend.
He previously spoke with Digital Spy about the epilogue, which takes place when the main characters are around 35 years old.
"Dan [Radcliffe] and I are very excited to see each other as old men!" he joked. "They're doing it with prosthetics, with me at least. No digital enhancements, it's all real stuff. I'm hoping it's going to be flattering, we'll see!"
Harry Potter And The Deathly Hallows: Part One is released in November.