Why would your bf tell another female that you are jealous of them?

If you have read my previous question, “Is it okay to text another female, “Good Morning Beautiful”?, you will understand more of where this question comes from. Shortly after the convo with my bf about the fact that he had texted another female, Good Morning Beautiful? I hoped that he would redeem himself, but I found where he had told the same girl that I was jealous of her!!! .. Omg I said are u kidding? The biggest thing is that I explained to him that I was disappointed in his actions and I didn't understand why he would text another girl .. Good morning beautiful … I clearly explained that I didn't want him to discuss this with her in particular, not to mention it to her, etc. The reason being that if she didn't know the whole story or even if she did .. it could come off in a way that it wasn't meant. I was more upset with him because the fact that HE sent it… the girl couldn't help but receive the message.. so how is it her fault or why would I be jealous? I was also angry at the fact that he tried to act as if he sent that message to her because he felt sorry for her .. because she had supposedly cried at some time saying she thought she was so ugly? (although all over her myspace page she had how beautiful and fine she thought she is) The fact that I deliberately told him not to talk to her about the situation, then he did and then he took it to another level telling her that I was jealous of her floored me. For some reason he can't understand how, for another woman to be told that not just another woman is jealous of her, but that your significant other is jealous of another her ..Makes that woman look like less of a woman. The next thing that bothers me is that he went out of his way to tell this girl that I was jealous; of course I am indeed not. But why would he take time out of his day to do something like that, as if he wanted to make her feel superior to me or like he wanted to boost her ego… I just have a hard time trying to see what was his purpose in doing that. It hurts deeply that he did it because we were friends for so long before the relationship and he saw how I have been hurt before. Any opinions? or maybe a reason he would do that?