Drunken sex or Rape?

Last night my sister came home very late. And Im the second oldest of 5 daughters 🤦🏼‍♀️ Anyways and my Mom is away for work somewhere over the sea and shes coming back mid October.. And I was the only one still awake when she came in (i was studying) she told me her Bf got drunk last night and he tried to have sex with her and she told me how he forced himself onto her took of her underwear and started playing and then eventually shiit went down.. she said he was way too strong and they had sex .. multiple sessions.. and she says that she just went with it cause she was scared he would loose it!! Some of her clothes are torn.. her bra is torn from last night.. she said in tears she asked him to stop but he wouldn’t listen .. and she didn’t want to make him mad. Cherry on top is. He didn’t ‘pull out’ .. she says that how many times she tried to push him off he would just keep going and keep c*****g in her and over her t*ts.. and apparently he just kept c*****g inside of her....

What do I do? What do I tell her? She feels disgusted!