I think my so friendship with another man[40ish] is crossing a line
Can you explain are you feeling too close?
Not at the moment. I'm not gay and neither is he.
It's good you're recognizing when far is too far, because if it crosses a threshold you can't ever go back. But if you two do have feelings for each other, you need to get courage and stop being in the closet. You may be losing out on an amazing relationship by trying to stay straight when you're not.
We are good friends, he lives in my neighborhood and I hang out with him occasionally. I'm not gay or anything. We are just hanging out and having sex. He doesn't know my real name.
Well that sounds suspicious. You can set boundaries so you don't get caught by other people they might suspect something going on. You could run your friendship if you think you are taking it too far.