What happens in Cabo doesn't stay in Cabo ... 'cuz Heidi and Spencer Pratt splashed their couple's vacay all over social media, and the two stars are gettin' down in Mexico!

More tequila, please! Heidi and Spencer took a break from parenting and indulged in some adult-bev fun -- Spencer cooled off poolside and doused himself with a margarita, while Heidi sipped a fresh one by the shore!

The dynamic duo hit the water in style -- Daddy Spence rocked some "I'll Do It" merch and Heidi blocked out the haters with a white ball cap and black sunnies!

Speidi are the latest celebs to soak up the Cabo sun ... Check out our gallery above and escape to Mexico with the stars!