Yeah, that's something that's been discussed quite a lot here. I personally can see how they, at the very least, understand each other in that moment because they both cheated for the same reasons, and with the same person for similar reasons, but I don't believe they should have forgiven each other so easily let alone professed their love for each other.
Obviously, this is a very difficult thing to write and I'm sure that even a skilled Hollywood screenwriter would be hard pressed to come up with a plausible way for a situation involving 2 girls who are in relationship with each other finding out they've both been cheating on each other with the same guy to be resolved, but at the very least I feel like they should have asked the question, "What does this mean for this?" You can't possibly go back to the way things were and say you love each other like nothing happened, especially Maya who's doing something with a guy for the first time.
But anyway, it's done now, DPC has tried to retcon it in ep 5, and we all just have to live with it.