Hi I'm looking for a manga/manhua/manhwa.

I have no idea what the plot is all about but the first 1 or 2 chapters goes like this.

The Seme attended a Reunion Party and he was approached by another guy(Seme).
That guy couldn't stop talking about how much he had sX with this Uke.
And the Uke is crazily in love with his D. (They are most likely just FWB)
ML Seme used to date that uke but during their relationship that uke keep lashing out that he used to be a straight or something.
The guy keep bragging but the seme seems completely indifferent during that chapter.

If someone have read about this please tell me the title Thank you.