Please,Please,Please help me out! What should i tell my confused Cousin?

Well my cousin told me about something that i really don't know how to help her with. She has a best friend (male, the same age as she is) that means a lot to her. She says she loves him as a friend. He was her only friend at one point in her life (and she's known him for about 2 years). It is very clear to my cousin that he loves her more than a friend, although she has never felt the same. Recently he started pressuring her to do sexual things with him. They eventually did these things, but never had an actual intercourse. I felt bad for him after she told me this and that she still didn't love him like he loves her. She said she just wanted to try these things with him and prove that she would do them. She said that she didn't know that it would make her feel "weird". She still wants to keep him in her life as a best friend, but he still loves her. She told him that they couldn't do those things anymore and she felt bad. Now she is feeling a little sad about it. She just told me that he was disappointed and that he felt weird when they did those things too, and he STILL has a crush on my cousin. What should she say to him to keep him as a friend? What should I say to help her?