The Justin Bieber Rehabilitation Tour has taken a detour through Motown Philly. After grinding a stage while singing the Boyz II Men panty-dropper “I’ll Make Love to You,†the Biebs did a much sweeter rendition of the song — this time for an engaged couple, as a TMZ camera stood waiting faithfully by. Wisely, Bieber realizes he probably shouldn’t keep singing about throwing clothes on the floor and lets the fiancé take over midway through.