GIRLS, Is it weird that this new situation with my girlfriend actually turns me on now?

My girlfriend and I have been together for 5 years. She is absolutely amazing and we have a wonderful relationship. She is very beautiful and I have become use to guys hitting on her and trying to get her number when she is at work or elsewhere with a couple of friends. I am not controlling or the overly jealous type and she respects and appreciates that. She is very straightforward and honest with me about everything and dosent like to hide anything. So a new co-worker of hers has been abnormally persistent at this. I have always known that she is physically attracted to black guys, so I naturally paid more attention to this situation. I asked her if she would like me to say something to him, and she said no she will try and take care of it herself like she usually does. A week later she tells me he has not given up at all. She said, I just do not understand why he likes me so much when he knows I have a serious boyfriend that I would never want to leave, and especially after being shot down a thousand times. I asked her if giving in had ever crossed her mind if this continues to be an issue? She said all she knows is it's really becoming a lot more stressful because he is so nice to her about everything. I said, I know you have a "thing" for black guys, are you attracted to him? She said yes, I am actually. I then asked, what do you think this guy wants from you? She said, if I give him my number he will probably want to date and definitely start having a lot of with me! I said, it sounds like you are mainly interested in that second part! She smiled and said he is really y babe, do you think you could possibly be ok with it if I let myself give in? And does it turn you on knowing now that I want to? I said yes, the thought of you giving in this time really does turn me on! I love you more than anything no matter what, and if it happens, you know I will respect and support your decision. I told her this is the best opportunity for her to finally satisfy her curiosity! She said, you know being completely filled up by a really well hung black guy has always been my biggest fantasy! I told her that I have also been fantasizing about her giving him head at work everyday since she first told me about him! She smiled and said I'm glad you have been thinking a lot about that, and if he asks me for my number again, which I know he will, I'll be more than happy to give it to him for you!