Justin Timberlake is sexy no matter what he does, but there's just something about him in dad mode that really gets our hearts racing. On Friday, the singer treated us to swoon-worthy Instagram video of himself playing with his 3-year-old son Silas's toy guitar. "Dad life. His toys = my toys. #pjmasks," Justin captioned it. If you listen closely, you can also hear what appears to be Silas talking in the background. So cute!