Mariah and Justin record a duet. The song ''Yours,'' featuring the newly solo 'N Sync singer, is one of several duets Carey is considering including on her album, due in December

Justin Timberlake is everywhere these days. The ‘N Sync singer is popping up at radio stations from California to London to promote ”Justified,” his solo CD debut due next month. But he’s also showing up alongside Mariah Carey on a duet called ”Yours,” which she may include on her still-untitled December release. The song marks one of several high-profile guest appearances on potential tracks for the album, including cameos by rappers Jay-Z and Cam’ron.

Apparently, the duet is romantic enough that both Timberlake and Carey have had to deny that they’re making beautiful music together outside the studio as well, reports. (Also, just for the record, Christina Aguilera has also denied that she and Britney’s ex are more than friends.)

In fact, Timberlake and Carey weren’t even in the studio at the same time to record ”Yours.” reports that producers Jimmy Jam and Terry Lewis recorded Mariah’s part first and Justin’s at a later session. Jam tells MTV, ”If I were to compare it to something we have done with her in the past, it would be ‘Thank God I Found You,’ but I think ‘Yours’ blows it away. It is probably one of the best hooks [ever]. I have a 6-year-old, and the first time he heard it, the third time the hook came around, he already knew it.” Carey is mulling over whether to include the pre-Justin version or the duet on her album, MTV reports.

Carey and Timberlake will appear on the same stage this weekend, along with such performers as Ja Rule, India.Arie, Jill Scott, Eric Clapton, and Elton John, for the taping of BET’s tribute to Stevie Wonder, which airs Oct. 29.