Khlo's still in Mexico this week with Tristan Thompson, and on Monday she took a stroll on the beach solo in a body-hugging one-piece. All we can say is DAYYYUMM (*smokey voice*).

She's definitely embracing her revenge body philosophy from last year, only now she's got a hot mom bod twist on it ... from the front and the back. Lordy, that's a whole lot of booty.

True story ... Tristan's got one hell of a woman on his hands here, and he should count himself lucky that she didn't curve him after his cheating scandal earlier this year.

She's certainly curving everything else ...