Justin Bieber appears to be holed up in New Jersey with Hillsong pastor and BFF Carl Lentz near the preacher's Montclaire home. The Biebs has been spotted by fans working out, jogging and strolling in a local park, keeping it on the DL with a hoodie and workout shorts.

Question is ... where's Hailey?! She's set to appear on The Late Late Show With James Corden Wednesday night ... but isn't that pre-taped. Why isn't she out on the east coast with her man?

The pair has been spending a fair amount of time apart as of late -- perhaps testing their relationship since they raced into an engagement, spending every minute together for a few months and then maybe decided they needed to pull back a bit and make sure everything's clear in their minds before staging a wedding ceremony with friends and family.

Hailey's already been hooking up with her wedding planner, choosing rentals; not to mention house hunting! The couple started their search together and then Hailey continued solo, checking out houses from the Valley to Brentwood and everywhere in between.

Could these two be cooling off? Re-evaluating? Is Justin getting some spiritual counseling from Pastor Lentz? We're guessing YES to all of the above ...