MJ's son celebrated his girlfriend Larsa Pippen's 49th trip around the sun with a photo dump of the lovebirds enjoying each other's company -- and we stress enjoying!

Jordan posted a clip where the 32-year-old is seen threading a Hookah mouthpiece through Larsa's top -- a low-cut black dress -- before taking a big ol' puff, all while the couple hangs out at an unknown club.

MJ exhaled ... and then did his best "Wedding Crashers" impression.

It wasn't all steamy videos ... Marcus also came with the prerequisite lovey-dovey-ness.

"Happy birthday to my best friend & partner in crime," Jordan wrote on one of the photos.

Larsa was clearly appreciative of the birthday love ... sharing posts from not just her bae, but from her friends, as well.

Unfortunately, it's not all cupcakes and rainbows for the couple. Earlier in the week, Michael Jordan publicly stated he doesn't support his son dating the ex-wife of his former teammate/frenemy, Scottie Pippen ... flat-out answering "No" when asked if he approved of the relationship.

With or without MJ, it's clear Larsa and Marcus -- who began dating last year -- are very much in love!