Buying a round of drinks is one thing. Keeping an entire restaurant’s glasses topped up all evening is another.

Champs champ 50 Cent is the kinda guy who does the latter, it seems.

Page Six hears that a festive-feeling Fiddy had lunch at the chic Si Si in East Hampton over the holiday weekend and spent tens of thousands of dollars buying his own Le Chemin du Roi champagne for the Memorial Day crowd.

We’re told he kept glasses topped up with his Le Chemin du Roi champagneSire Spirits/Andres Puerta

We’re told the rapper arrived sans reservation and immediately decided to begin sharing the champers.

50 Cent performed for a chic crowd at Surf Lodge in Montauk on Saturday in front of guests including newlyweds Millie Bobby Brown and Jake Bongiovi, Liev Schreiber, restaurateurs Rich Torrisi and Mario Carbone and newly single Sports Illustrated Swimsuit cover model Brooks Nader.

He also performed at Surf Lodge over the holiday weekend.Sire Spirits/Andres Puerta

We’re told that once again the rapper’s bubbly brand was flowing during his surprise set.