Idk if you already reached the chapter where the ML briefly shared how his family treated him growing up, but craving attention or suddenly feeling deep affection towards someone who's showed you warmth which you have always lacked during childhood is normal. It happens irl, they'd crave it more and even depend on it because that feeling is completely foreign.
It's typical for them to grow up being either overbearing or apathetic. ML was the former.
I've had similar experiences wherein my former classmate couldn't stand the thought of not being in a relationship so she'd always find a new partner every after break-ups. I then came into realization after she shared how her father was never really around and her mother not being affectionate towards them during her childhood, hence, how vulnerable and lonely she feels when she don't have a partner whom she can share her burden. She told us it felt different when you have someone you be with and rely on.
Well I don't know it much in a deeper sense but you'd somehow get the gist. ML must've felt the same. He must've also felt very lonely. Let's not forget how our childhood environment can always affect what we'll become. /gen
Ch 9. My first time re reading this but now I'm kinda turned off at the ml. He acted like his ex was the love of his life then did a 180 with mc... I kinda feel bad for the ex low-key. It did seem like the ex did his best in the relationship maybe ml is just being too much.