The First Time

Dave and Aubrey meet on a Friday night in an alley outside a party and Dave seeks Aubrey for advice about a girl that Dave likes, Jane. When the cops arrive, Dave and Aubrey evade the party and walk to her house. When they get to Aubrey's house, she invites him inside. Aubrey randomly asks Dave if he's had sex yet, to which he replies that he hasn't. When he asks her the same question, she refused to answer. After their conversation, they fall asleep together in her room and when they wake up the next morning, Dave escapes through her bedroom window.Talking to his friends, Simon and Big Corporation, about Aubrey, they think she lied about having a boyfriend and tell him to text her, only for Dave to discover he doesn't have her number. They decide to call a guy who has access to Aubrey's high school student database, who gives Dave Aubrey's home number. When Dave calls Aubrey asking her what her plans are for the night, she says she's going to the movies with her boyfriend Ronny, to which Dave responds that he is also going with his friends.At the cinema, Dave bumps into Jane and her friends and discover they are seeing the same movie. When Aubrey bumps into Dave, she introduces him to Ronny. Aubrey and Ronny then go see the same movie as Dave and Jane. When Aubrey leaves during the film, Dave follows her into the lobby where she apologizes for being rude to him on the phone earlier and making him jump out the window that morning. Dave forgives her by finally getting her cell phone number and invites her and Ronny to a get together at Jane's friend, Brianna's, house. They then go back inside and continue watching the rest of the movie.At Brianna's house Aubrey and Jane have a chat where Jane reveals that Dave is her best guy friend who always listens to her about her relationships. After hearing what Dave says about Jane over the past days, Aubrey begins to suggest Jane go out with Dave but then stops half way through her sentence.Ronny reveals to Dave that after waiting a long time, that he is going to have sex with Aubrey in his van that night. Dave then finds Aubrey and asks her not to lose her virginity to Ronny claiming that he isn't the right guy for her. Aubrey then declares that there isn't anyone right for her and that she wants to get it over with. Dave doesn't believe this and claims that she likes him. As they are about to share a kiss, Ronny interrupts wanting to leave immediately. Dave and Ronny get into a small fight and Aubrey leaves with Ronny.Dave is then alone with Jane, and whilst tending to his wound from his fight with Ronny, Jane begins talking about her relationships. Upon realizing his growing feelings for Aubrey, and that whenever Dave and Jane have their chats, all they ever do is talk about her, Dave leaves. On his drive home, Aubrey texts Dave asking him to pick her up. On their drive around town she reveals that she broke up with Ronny, and they share a kiss.The next night, Aubrey's parents go out for the evening, and Aubrey invites Dave over. Dave decides against bringing a condom in case they do have sex. He rebels against it, and goes to her house. When he arrives, they start making out, but Dave stops it claiming that this has been the best weekend of his life and he doesn't want to ruin it. They then state that not having sex is the better option and is much better for their relationship. They then decide to have sex anyway, despite what was just said. However, it doesn't go as smoothly as they planned, leaving them both confused about their relationship.Dave then seeks advice from Simon and Big Corporation, and whilst Simon tells him to move on as their relationship was never going to last, Big Corporation says to be a man and not to bail because of one little mishap.The next day, Dave comes to Aubrey's house and says that he wants to be in a relationship with her in spite of what happened the previous night. Dave then drives Aubrey to school. When they arrive and Aubrey walks to her first class, despite saying to Dave when they first met that she hates public displays of affection, she runs back to Dave and kisses him.

Question: Who is Jane's friend?
Answer: Brianna