I didn’t read this manga yet. But I saw some spoilers saying the ML is having a physical...

There is no such thing, at least not in the manga as far as it's been updated. ML has only ever slept with MC, but he had one-sided feelings for MC's brother at first (never got physical).

MC’s half brother used to be ML’s first love and he helped him at first out of love. They do not have and never have physical relationship. The Hlaf bro knows Liyu had feelings for him and manipulate him using that.

Thanks a lot. I didn’t want to get started if it were that kind of love triangle.

Thanks a lot.

Spoiler* in the novel the half brother takes advantage of MC. Assaults and kidnaps him. So while not consensual they did sleep together