My husband died almost 20 years ago and I have not been interested in looking for another relationship. I could never have responded like this back when I was, but it seems to me now, since I'm not in the game and have no anxieties, that this could be the occasion for a joke:

"Oh, you are on match, too?"

Then, him -- maybe "yes, would you like to go out sometime?"

And then, you: "No, I don't date people at work but thanks anyway. " Adding, if he seemed at all appealing otherwise, "But maybe we could meet for a cup of coffee/tea sometime?"