Buckle up and sit back and enjoy, folks ... we've got a MASSIVE Justin Bieber - Hailey Baldwin all-day event for you!

So let's run down exactly what happened Friday with the young newlyweds ...

The couple gets into a heated discussion at Blue Bottle Coffee over Hailey's decision to work out at Selena Gomez's favorite West Hollywood Pilates studio. In fact, they ended up walking home separately. Apparently it hits a little too close to home for Justin and feels it could throw Selena off even more than she already has been. After Jailey got married, Selena found herself in psychological treatment and she's been MIA ever since. When she sees Hailey's not only taken over her man, but her favorite workout spot, well ...




Hailey won the fight because guess what she did next -- she threw on some sexy white leggings, a "Drew" hoodie of Justin's design, some hot Balenciaga trainers and left the couple's Montage residence to head to Selena's Pilates studio with some pals ...



Hailey and her squad showed off their insane bods for the paparazzi as they left the Pilates studio and headed home. Hailey gave an exasperated look as photographers yelled out questions -- but hey, Hails, what do you expect?! You're at Selena's studio! ...




Hailey rolled up in the couple's matte army green G-Wagon and Justin confronted his wife and guess what ... THEY KISSED AND MADE UP!





Finally, Justin decided to channel this energy into his work so he grabbed his laptop and hit the recording studio ...