The couple wrote the duet together for Mayer's new album "Paradise Valley", which is releasing on August 20. The song gives an insight into the on-again couple's attraction for each other, reported People magazine.
Perry said her laugh at the end of the tune was "just a love giggle".
"It's like the ones that Mariah Carey had in 1990. I was going for that, I think I was just so happy ... You're catching the real moment there," she said.
Mayer has previously dated Jennifer Aniston, Jessica Simpson and Taylor Swift while Perry ended her marriage to comedian Russell Brand after 14 months.