Don't you love finding out about a celebrity's secret talent? In the case of Jessica Biel, it looks like one of her lesser known abilities may be overshadowed by her husband's. Justin Timberlake may have made a career out of singing — but Biel has a pretty damn good voice too, as it turns out. The actress gave an impromptu mini-performance on the red carpet at the premiere of The Book of Love on Tuesday. Biel, 34, sang a snippet of "Happy Birthday" (the Stevie Wonder rendition) to E! News anchor and birthday boy Marc Malkin. A stunned Malkin suggested to Biel that she do a duet with J.T. — and apparently he's not the only one egging for a collab. "My mom won't stop with the duet!" Biel said. "I'm like, 'Mom, it's not going to happen. It's not going to happen, Mom.'" But apparently Biel and Timberlake already sing together, to a very special audience of one. "It's more like the bedtime routine, like singing the baby to sleep," Biel said. "That's really where the duets happen." You're a lucky little dude, Silas.