Lucy is Simon's love interest in The Inbetweeners Movie.
Lucy is friends with Alison, Jane and Lisa. They first appear traveling through Malia. Lucy's judge of character is questionable, as she takes an instant liking to Simon despite barely knowing him. She's a romantic at heart, even offering her party ticket to Simon so he can get with Carli.
After a year of dating Simon, Lucy has changed completely. She's now clingy, jealous, paranoid and downright abusive. She's also unfaithful, cheating on her boyfriend even when she's planning their wedding.
Carli was Simon's ex-girlfriend. She dumped him shortly before going on holiday. The boys take Simon on holiday with them as a way of taking his mind off her, only to find out that Carli was holidaying in Malia as well. Lucy was obviously insecure about being second-best to Carli. Deep down, Simon seemed to love Lucy, but since he'd been chasing Carli so long he thought that he was still in love with her.
Lucy met Simon while on holiday in Malia with her friends Allison, Jane and Lisa. After Simon, Neil and Will embarrassed themselves by dancing over to the girls in a nightclub, Simon sits next to Lucy and right away she takes a liking to him. Unfortunately, Simon bores her by talking about his ex, Carli.
The next day, Simon and Lucy meet at the hotel pool and Lucy tells Simon about an upcoming boat party. Simon asks if she can get him a ticket so he can chase Carli. Offended, Lucy leaves him. That night, Simon runs into Lucy at the nightclub and they patch up over drinks. Lucy and Simon go skinny dipping and are about to kiss when Carli appears and Simon decides to go talk to her. Lucy goes home upset.
On the day of the boat party, Simon apologises to Lucy for being so self-centered. Lucy, realising she doesn't stand a chance against Simon's ex, decides to give Simon her ticket so he can make one last attempt with Carli. Not realising the implications of such a gesture, Simon takes her ticket and runs. After finding out that Carli wasn't the one, it dawns on Simon that Lucy was the one he wanted to be with. Knowing that he'd pushed her too far away, Simon decides to make a big declaration of love by swimming to shore and kissing her on sight. Everyone cheeers him on while he swims, but he tires after a few metres and nearly drowns. After Simon is rescued and about to be put on an ambulance, Lucy kisses him.
Simon and Lucy then spent the rest of their holidays together before going home. At the airport, they meet up again and Simon introduces her to his parents.
A year later, Lucy and Simon are still together, but Lucy has become jealous and abusive. She attacks any girl Simon talks to and destroys all of Simon's possessions for no reason. When Simon goes to Australia with his friends, Lucy tells him to Skype her every day to make sure he's not cheating on her.
Simon accidentally says the words "Will you marry me?" during one session, which causes Lucy to jump to conclusions and start planning a wedding. Lucy still treats Simon badly, telling him that none of his friends can be the best man because she like Simon's roommate Pete better.
In the end, Lucy admits that she and Pete have been sleeping together. Simon cheers at this bit of news, the happiest he's been in a long time.
Pete is Simon's roommate at university. He's a smug pretty-boy and clearly has his sights set on Lucy. While Simon is away, Pete starts spending more and more time with Lucy, convincing her that he's Simon best friend despite Simon's loyalty to Jay, Will and Neil. Eventually Lucy and Pete have sex, which Simon takes great joy in finding out, since it means he's off the hook and that Pete will soon get his come-uppance for going behind his roommate's back.