Is it only right to do this for him?!?

Me and my boyfriend were together for 3 months. He`s away at college, and we haven`t started dating until he left. Sadly, I haven`t got to see him before he left since I`ve connected with him through his cousin who I know personally. So we`re in a long distance relationship. Everything was great, then out of no where last week, he started asking for naked pictures. I had a bad experience with that before and I mentioned that to him.. He explained to me not to worry that he`ll keep it to himself.. but he continues to ask me about them. I wouldn`t say our conversations revolve around it, but I just want to know why he wants it so bad. Is it only right that I send it to him?