Beyoncé knows how to keep people guessing, even with her e-mail activity. After collaborating with Queen Bey on “Perfect Duet,” Ed Sheeran revealed that it’s not easy to reach the LEMONADE superstar.

“I have an email address that I email [to get in touch with Beyoncé] that actually changes every week,” he told “Entertainment Tonight.” “She’s very good at [hiding]. It’s kind of what I aspire to be.”

Sheeran went on to say that the song has been in the works since May. After she delivered her twins Rumi and Sir, the duo got back in the fold to complete the track in September. “I’ve been holding onto it since then,” he said.

Going more in-depth about the collaborative process, Sheeran revealed how ‘Yoncé made the song her own. “The original version of ‘Perfect’ was just an acoustic guitar and she rung me up and was like, ‘I don’t know how you feel about this but I’ve taken all the instruments off it and it’s just gonna be acoustic guitar,’ and I was like, ‘Ah that’s great, because it used to be that!'” he explained. “Then when we got in together, it wasn’t so much notes, it was very much like a back and forth thing, like, ‘What’d you think of this?’ Or ‘What do you think of this?’ and [we were] probably in the studio for four hours. She was just like, ‘Right!’ Went in, one take, came out, like, ‘Yeah, that sounds alright!'”

“Perfect Duet” is a remix to “Perfect” off Sheeran’s latest album, ÷. In the past, Beyoncé and Sheeran performed a Stevie Wonder tribute together during a 2015 Grammy special and they teamed up for a “Drunk in Love” duet at the Global Citizen Festival in 2015.