Memorial Day tradition! Three weeks after welcoming his first child, daughter Briseis, with fiancee Lilit Avagyan, Reggie Bush headed to Las Vegas for the holiday weekend.

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Bush, 28, tweeted a funny photo of himself hanging out poolside in Sin City on Saturday, May 25. "No filter. Vegas. What is he doing?" he wrote, commenting on a man swimming behind him.

A source tells Us Weekly that the Detroit Lions running back "has been partying in Vegas for years on Memorial Day."

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The new dad recently chatted with Us about how he's adjusting to fatherhood. "I look at [Briseis] and I can't believe she's mine," the NFL player said. "There's still that element of I can't believe this came from me."

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"She's doing great," Bush added. "She's amazing. She's so beautiful. I love her to death. It's just been an amazing experience so far so I'm very excited -- just being a father."

This article originally appeared on Reggie Bush Parties in Las Vegas Three Weeks After Baby Briseis' Birth