One of a number of "Hamilton High" novels, sort of a teenage version of After School Specials on everything from teen pregnancy to coming out of the closet to being molested by the father of the children you're babysitting. This novel deals with standing up for yourself and the impact of substance abuse. It was written in 1996 so in some ways it is dated (such as the reference to Barney) but the basic premise is still valid.
Erica is a high school senior who wants to be a vet, so she volunteers at a local clinic. Her dad is stationed in Germany so it is just her mom and younger sister at home. She has been dating Danny for a while. Unfortunately his mother is killed in an accident and Danny falls apart. He drops out of school, starts drinking and dealing drugs, and is eventually kicked out of his house by his dad.
Erica remains with him, constantly excusing his behavior because he's still in mourning. This means that she constantly gives in and does what he wants to do, which typically for him means him getting drunk and having sex. She hides condoms and spermicidal foam in her closet (which her grandmother finds) because he insists on climbing through her window at night. Despite her grades falling and the strain on her relationship with her parents and friends she doesn't tell him no.
Finally things implode on Christmas when she goes to pick him up at the drug house he's sharing with his buddies. He's coming to Christmas dinner and supposed to be sober because her dad is home. Instead when she gets there she is raped by one of the roommates because Danny is too drunk to know what's happening or intervene. So she gets to spend Christmas at the hospital followed by the police station.
She retreats into her room and bunkers down. Her parents didn't like Danny anyway so they cut him off when he tries to contact her. He finally talks her sister into delivering a note from him. When she reads it, she realizes it is all about him: he's dumb enough to say "I feel so awful about what happened, but that's over now" and he's missing her so he wants to come through her window for sex (he promises he'll be quiet so her dad won't hear. What a prince!). No admission of responsibility, no acknowledgement of her suffering. This finally makes her realize that everything has always been on his terms and that is changing now. It is finally time for her to say "But what about me?"