In this movie...

Justin Timberlake is seen naked as he is having sex with Mila Kunis. In a first scene, he undresses and we can see his butt, although dark. He is seen undressed in several other scenes. Justin has an amazing body. In a following scene, we see his butt very clearly as he rushes to the bathroom. As a woman walks on Justin having sex with Mila, we see him naked again. There is one frame, where we can see Justin's dick before he puts his underwear on. He appears to have a fairly long cut dick.