Alison is Will's love interest in The Inbetweeners Movie.
Alison and her friends Lucy, Jane and Lisa were on holiday in Malia when they ran into the boys at a night club. All eight pair up, only to wind up in several awkward scenarios.
Alison is most likely the leader of her gang. She's confident and handles most situations in a calmer manner than the other characters, but also has a fiery temper when she's upset.
Will takes a liking to Alison when she allows him and his friends to sit with them. Alison's sharp wit makes her a natural mathc for Will, but as she had a boyfriend at that point, they could only stay friends. After Alison finds out that Will is a virgin, she offers to sleep with him in a year if they're both still single.
When Alison dumps her boyfriend for cheating on her, she alters her offer so that instead of having pity-sex with Will, she becomes his girlfriend. Will immediately says yes and they become a couple, though they break up at some point and Alison is never seen again.
Nikos was Alison's Greek boyfriend. They had a passionate relationship that Alison was all too ready to brag about. Will suspected that Nikos was a player and Alison was just one of his many girlfriends. When Alison decides to go skinny-dipping with Will and the others, she comes across Nikos having sex with a girl. Angry, Alison storms off. The next day, she tells Will that they broke up.