Is it normal that my boyfriend asked his ex to help him with a gift for me?

My boyfriend had a major crush when he was 15. The girl also loved him but she moved out to another city and he still loved her for another 5 years, until I met him (he was now 20 years old). On the other hand, she did move on quickly and had other boyfriends. They stayed in touch and they still are. I read a facebook chat conversation she had with him and he always tells "hi" first and strictly just talk to her about me. He tells her every detail about us and he even asked her to teach him how to cook a cake that I love that he was going to give me as a Christmas present. They never talk about anything else, sometimes a regular "how are you?" but 90% of their conversation is about me. In general, he tells her everything he wants to give me, how our dates are, how great I am and how happy he is. He always speaks amazingly good about me and even tell her she is wrong when she criticizes something about me. But, he ussually avoids the subject when I try to ask him about her. And once he deleted a facebook comment she made because he thought I might got angry (why? I've never said anything about any of his friends that are girls). I think he felt uncomfortable because he still has feelings for her.

I am trying really hard to not be the jelous type and I don't mind if they are friends, but I just have the feeling that because he always says "hi" first and because he asked her to help him, something is wrong. I believe it is very weird that he only talks to her about me!!
Is this normal or am I being paranoic?

Thanks! And sorry for my English, not a native speaker.