Can you understand this girl? what should i do?

I will be honest...it doesn't sound good. I knew a girl before that wanted to believe in me, but she had gone through some rough stuff. She gave me a few sexy pictures of her and asked me to masturbate about her and that she would phone me as well. I thought it was some sort of test, and i played along. When she did phone, she wanted me to do it ...but... i found she was doing it too...i found it a real turn on. We got closer and closer and our relationship developed. Would you do anything like that with your boyfriend to keep him loyal, while you are apart?