
I love the flow of the story. But serious question can you really forget your feelings to someone just by having sex to various people? Because I read many mangas like that .

Mangas aren't real life. Real life and real people are complicated so it depends on the person.
Now, if you're asking why lovesick characters sleep around, that's because sex lets out pleasure hormones that make you temporarily not feel miserable anymore, hence "sex to forget".
Why I'm always expecting a virgin character in a omegaverse story? Oh my heart and soul...
hyesung is virgin but he was taken by dojin when his heat came
Well that's given. It's hard to find a virgin seme in a manga nowadays . Thanks though