Guess the Sexy Singer in This Reflective Bikini

Here's a good way to pass some time on your Monday ... guessing the sexy singer in this reflective bikini!!!

This smoking hot babe is one of Colombia's finest exports ... she's big in Latin America and pretty popular in the States too.

She was missing from Instagram for about 4 months, and just came back with a vengeance ... posting a bunch of sexy shots that we're showing you here.

We definitely missed her -- and her hot bod -- and are glad she's back ... so check out the gallery to see what we're talking about.

Her biggest songs include "QLONA," "PROVENZA," "TQG," "+57" and "Si Antes Te Hubiera Conocido." Not Becky G, but ...