<human>: Can you condense the text into a few key points?

So my gf and I have been dating for about 8 months now, and everything is great. An issue arose in the past (about 3 months in) where she revealed to me that she still talks to her ex boyfriend quite regularly. This wouldn't be an issue at all, except up until that point she had made sure to tell me that he no longer lives the the same city we do, and that she has no desire to have conversations with him. But whatever, I got over that quite quickly because it's a non-issue.

The issue now is that this morning I found out that her ex does not know that I exist. My gf has been talking to him once every week or two on Facebook for the entire 8 month duration of our relationship (as well as before we even met) but has never once mentioned me or even the fact that she is dating someone at all. So when I found out about it, I got a bit upset, and asked her to please tell him about me immediately, or else I would have to suspect that something is up. To me, if you are friends with an ex, they absolutely have to know when you are dating someone, especially after you have been dating someone for 2/3 of a year. My gf agreed to do it, but she also said that she doesn't feel like it's something that she should be obligated to do, since her love life is none of her ex's business. After she said that I started to feel guilty about my request. Did I make an unreasonable request?
<bot>: GF hasn't mentioned me to her ex that she regularly talks with. I asked her to tell him about me, but now I feel guilty about it. Is my request reasonable?