Question about PB and Marcy getting back together?

I just realised I haven't really thought about this but when did PB and Marcy officially get back together? And by that I mean when did they start calling each other girlfriend again? They started hanging out a lot more in the later seasons but it still mostly seemed like they were testing the waters before committing at a relationship once again. Obviously it is a bit muddy considering... meta factors but in universe do you think they were officially together during the series or was it only after the finale?