Amanda Bynes is shown arriving at Zac Efron’s birthday party at Pace, in L.A. Bynes wore a sexy, short, three piece suit. Efron celebrated his 21st birthday last weekend. It was a small party with family and friends. Some of Efron’s celebrity pals were Vanessa Hudgens, Monique Coleman, Ashley Tisdale, Brittany Snow and Amanda Bynes. After the meal, some of the guests proceeded to a hotel nearby to carry on partying. Efron was reported to have received some bottles of booze for birthday presents, to signify he has reached the legal age for drinking in the U.S.