Pia Mia Spends Halloween Beachside in a Sexy Bikini — See the Star’s Sexiest Pics!

While everyone in Hollywood transformed themselves into creepy characters for Halloween, Pia Mia spent the day at the beach!

The singer took to Instagram Monday to flaunt her bum in a sexy bikini, which appeared to be her costume of choice on the spooky day.

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The 20-year-old singer, who has worked with artists like Chris Brown and Tyga, is definitely a sight for sore eyes, and we've rounded up some of her sexiest Instagram photos in the gallery below!