Ben Foster & Laura Prepon Sighting Suggests Wedding Day's Getting Close

Ben Foster and Laura Prepon appear to be inching closer to husband and wife -- 'cause they hit up the one place in NYC they gotta go to make it happen.

The couple of about 2 years waited in line this week for the City Clerk, where marriage licenses are issued to residents. We don't wanna get ahead of ourselves -- there are lots of reasons Ben and Laura could've been at that office.

Maybe they were enrolling as lobbyists, requesting City Council transcripts or submitting their Oaths of Office as elected officials. Okay, definitely not the last one, but you get the point ... marriage license seems to fit the bill here.

As we reported ... Ben and Laura announced their engagement by flashing her massive rock in the fall of 2016. They already have 1 kid together.

We've reached out to their reps, but no word back yet.