On the production level, i totally agree with @steve70 its probably scheduling conflict. Kproduction really has yet to get the hang of multiple season dramas. They usually do spin-offs. So the new FL chracter is probably a way to add new content to the story so it will not feel stagnant/redundant...?
But on a story level, he maybe friendly and chatty with the women in general but i dont think he qualifies as a playboy. He probably is the more realistic Male character in that in real life, you can have your first love, your second love, and third, and fourth and then last.