Sydney Sweeney Flaunts Booty in Sexy Lakeside Pics

Sydney Sweeney’s solidifying her Hollywood sex symbol status with a day out on a lake, and despite all that water ... she's feeling thirsty, and damn proud of it.

The actress rocked a super cheeky athletic swimsuit, zipping it down just enough to flaunt her famous cleavage -- but for once, she's shining the spotlight a little further south ... on her booty!

The pics -- taken during a boat outing with friends -- are pretty freaking hot, and intentionally taken from every angle.

Syd unapologetically wrote in her caption, "I think they call this a thirst trap."

Yup! That checks out. 💯