Johnny Manziel's Wife Bre Tiesi Flexes Butt Muscle Poolside in Bali

Bali is known for its incredible views ... but Johnny Manziel's wife just made it MUCH better ... showing off her booty flexin' skills in a bikini by the pool!!

Bre Tiesi is in Indonesia with her friends celebrating Jordan Ozuna's birthday ... and naturally, that means everybody's ditchin' their clothes for their suits to get some fun in the sun.

No sign of Johnny on the trip ... and no offense to the QB, we're perfectly fine with that.

Of course, Johnny's had fun with the crew in the past -- who can forget their epic topless beach trip in Mexico in 2017?

The girls posted all the (clothed) fun this time around ... from impromptu photo shoots to celebrating the birthday with some cake.

As for Ozuna -- she's Bre's business partner and has been linked to Tyga and Justin Bieber in the past.

Happy birthday ... to everyone!!