Barely Legal (2011) on Netflix

Sue, Cheryl and Lexi are three college freshmen who have been best friends since they were born on the same day. They do something special every year for their birthday, but on their eighteenth, they set out to lose their virginity. They throw a large poolside party at Sue's house hoping to "pop their cherries" before the day and night is over. But they find that losing their virginity is easier said than done as all three of them embark on a series of raunchy and hilarious quests to do so.