Is it a numbers game?

Do you bring it up or not? The *number*. I am still struggling with this. Is it bad to not let the 28 year old know that you're nearly a decade his senior? I mean, it's not like I am going to marry him right? I may not even see him naked. I have answered my own question, as I let the struggle dissolve into non-action. Here's how it started, and let me state this never happens to me. Well, it did happen, but let's be clear here, these things tend to NOT happen to me.
I go the gym early. Not sunrise early, but starry night early around the neighborhood of 5:30am. I'm groggy, disheveled and cursing at myself the whole way there. Wondering if I can really have a productive work out when I can barely feel my legs, knowing that I must as I won't have time later - that, and I enjoy it once I get going. I silently grunt, peddling my feet on the hamster wheel that is the elliptical. On this particular day, as surge of energy manifested post-cardio and I decided to lift. I don't worry about how I look at this gym, for the reasons mentioned above AND the fact that I live in the gay area of town. Which is great, fantastic eye candy, and no one to bother me at said gym. I just like to get in and out. so I didn't pay any mind when I saw hot green t-shirt out of the corner of my eye as I packed up my bag to head home.
Then I noticed green shirt coming closer. To me.
He stuttered and stammered and me, high off of my endorphins, smiled, let the sweat drip down my chin, because surely this young man was gay.
And then it happened.

"Can I take you out for coffee sometime"
Whaaaa?
Of course I said yes, he was a snappy looking guy and that took major balls...and he asked me out sans make up and drowning in my own sweat. Repeat: this does not happen to me. Ever.
Fast forward to our 'date'. It was nice. Yes that's it "nice", good conversation, cool guy, but no spark. See, I can talk to anyone, because I like talking to people. I want to know about how they think, what they care about. I like to figure out how I can relate and watch the dialogue escalate. This does not mean I like you, like that anyway. In talking with green shirt, I realized he was much younger than me. I just felt it. I continued to delude myself in thinking this guy didn't like me, but he did walk me home and nervously planted a big smooch on my lips as I flitted up to my apartment.
Yes, you probably know what I did next, I FB'd (Facebooked) him and sure enough, he's almost a decade younger than me.
He wants to take me out for a meal of some sort. That would be nice, maybe. Maybe not. A chain of emails and a week later I've postponed our date. I have my answer, I'm just not that into him. Like that. So I plan on going out to dinner, we'll go Dutch, and I'll just let him know. Hope to be friends, we'll see what happens.