Olivia, Sophia Culpo Cheer On Their NFL Boos in 'Battle Of The Boyfriends'

It was the Culpo Bowl between the Carolina Panthers and NY Jets on Sunday ... 'cause Olivia Culpo and her sister, Sophia, got to watch their NFL star boyfriends face off against each other!!!

Of course, OC has been dating Panthers superstar running back Christian McCaffrey for about 2 years ... and her little sis went "IG official" with Jets WR Braxton Berrios back on Valentine's Day.

So, when the Jets and Panthers faced off in Charlotte in Week 1, the Culpo sisters had to split up and root for opposing teams ... and there was plenty of friendly smack talk.

"Kiss my ass," Olivia told Sophia while flashing her butt ... as Sophia responded, "Oh we'll see, sis. WE. WILL. SEE."

Ultimately, the Panthers came away with the 19-14 win ... but both guys balled out.

CMC had 98 yards on the ground and added 89 receiving yards ... and Berrios had 5 receptions for 51 yards.

The foursome definitely enjoyed the offseason ... taking several romantic trips in paradise.

No matter what happens during the 2021 season, one thing's for sure -- Braxton and Christian are both winners off the field.