The Song I Like -는

-(으)ㄴ 후에 already showed you a verb taking -ㄴ/은, but only ever glued in front of 후에. On its own, that same ending modifies a noun with a completed, past action instead of an ongoing one: 만난 사람 is “the person I met,” not “the person I’m meeting.” Swap -는 for -(으)ㄴ and the whole clause moves into the past.

지금 만나는 사람 있어요? is the standard, indirect way to ask if someone’s dating anyone. It leans on 만나다 doing double duty, the same verb used for a plain social “meeting,” now carrying a romantic implication purely from context.