Kourtney Kardashian strutted her stuff in Mexico ... and need we say the obvious ... super hot.
Kourtney was on vacay in Cabo with a butt floss bathing suit that is hanging on for dear life.
As for who she's with ... her trainer, makeup artist Hrush Achemyan, Sarah Howard, and her good friend Stephanie Shepherd -- she's Kim's former assistant.
One person who's not there ... ex-BF, Younes Bendjima, who has his own issues these days after video surfaced of him beating the crap out of someone at Delilah nightclub in WeHo back in March.