Hailey Baldwin didn't look too excited to be off traveling on her own Sunday, having to leave fiance Justin Bieber behind in LA while she jets to the east coast for modeling work. We don't blame her!

The pair were betrothed July 8 and have spent every second together since but hey, when work calls, the supermodel's gotta get going!

Meanwhile, Justin's left alone in LA and fans are pointing out that it was SELENA GOMEZ'S 26TH BIRTHDAY YESTERDAY!!! Um, you think JB will head over to her house and drop off a present? Doubtful -- that'd be the fastest way to lose a fiancee that we can think of. Justin's got his head on straight and his heart in the right place and there's NO WAY he'll reach out to Selena right now ... right?