Charli xcx is giving fans a very cheeky look at her lakeside getaway ... posing solo in a skimpy bikini.

The "Brat" singer kicked things off facing the camera in the teeny two-piece and bright pink heels ... striking a pose with her hands in her hair.

Then Charli turned around -- making sure the bikini looked just as good from behind.

She finished the photo dump perched by an open window overlooking the lake ... serving up quite the view herself.

Charli's made a habit of keeping things hot ... and these lakeside snaps are right on brand.

The Instagram post was captioned, "a girl on a lake with her friends and her husbands !" ... though she made damn sure all eyes are on her.

The scenery's got nothing on Charli in a bikini and heels.