What would be the best way to handle this situation?

[MM]

Tell him no. You are not interested in cultivating a closer friendship, and you do not want to socialize with him unless it is in the company of your friend. You also do not understand why he says he wishes he had met you before Nicole, because you are not interested in him the way Nicole is - and if that's what he's getting at with these invitations, he needs to back off before you let both Nicole and his wife know what he's been saying. If his intentions are genuinely innocent, or he has any sense, he'll let it go. But I think you know perfectly well they're not, and he needs to know his little game's not going to work on you.