Celebrating his birthday with two of favorite people! After turning 34 on Wednesday, June 5, Pete Wentz partied on the beach with son Bronx and girlfriend Meagan Camper in Miami, Fla.

The Best Ink host showed off his tattoos in black swim trunks while splashing in the water with his 4-year-old son, whom he shares with ex-wife Ashlee Simpson.

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Wentz's model girlfriend Camper, 24, showed off her stunning beach body in a bright red bikini with a sexy fringe top. The couple, who began dating in September 2011, grabbed Bronx's hands and swung him around in the waves.

Since their divorce in 2011 after three years of marriage, the Fall Out Boy rocker has maintained a friendly relationship with Simpson. During an appearance on Bravo's Watch What Happens Live, Wentz praised Simpson on her mothering skills.

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"I feel like we both realize that we're parents and we're in it for our kid. That's made it really easy," Wentz said of the singer, 28. "I feel like, as a mom, she's awesome. She's an awesome mom and we get along really well when it comes to our kid now."

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Simpson is currently single after splitting from Boardwalk Empire actor Vincent Piazza in November 2012.

This article originally appeared on Usmagazine.com: Pete Wentz Plays on Beach With Son Bronx, Girlfriend Meagan Camper Shows Off Sexy Bikini Body