Justin Bieber and Hailey Baldwin attended their usual Hillsong church service last night, but they left in separate cars ... why?! Does that mean they're not staying together at home?!

The two exited at the same time, Hailey a few steps behind and looking a bit down. Justin was all smiles but didn't look back as his wife hooked up with a girlfriend and left in that friend's car. Was she having a sleepover with a pal because she's not living at her marital home?! Maybe she and Justin are saving themselves for marriage now that they have a wedding date in just a couple weeks ... perhaps they're not living together as a way of making the big day more special? What gives?