Of what we know that encompasses the past 4-8 weeks, I highly doubt Maya cheated on Stepan. Why they stayed in the same apartment (platonically) for the past few weeks we may never know. Don't even know why they split but I doubt its because anyone cheated on the other. My guess is Maya tired of their relationship. He always seemed lazy to me while Maya likes to keep active. But we do know they had no relations, they were barely speaking to one another and they slept apart.
What surprises me (and some of this is based on personal experience) is (and yes, I'm judging Maya based on what we can decipher) is how quickly she could sleep with another guy. I know after I split from a g/f that I had dated for a few years, it took me several months (maybe close to a year) before I was comfortable going into another relationship (sexually & emotionally; different that having a one-n-done bang). Clearly she banged this guy before and you can tell by their behavior its a new situation for both.
Let's hope we see a different Maya that we (I) have seen the past 4..5 years. One that smiles more, laughs more and is a bit more open about who she is.
As for Leora & Paul,...Paul, Maya has indirectly put you on notice (even though Leora & Paul's relationship is more deeply routed and was always stronger than M & S).