Forgotten Title BL World Hopping / cant remember novel

Hi so I'm looking for an arc in a world-hopping book and here's what I remember

The ML? gets reborn and put into a body that happens to be MC's secretary. (MC and ML? were lovers)

The ML? believes that MC is the one who caused his death so he watches MC see how he acts (he's being all creepy and shit stalking him with cameras)

The MC has to sleep (till it rots and he gets him cremated) with the ML's? OLD body to show ML? (who put up cameras) that he is truly heartbroken with ML's? eath, making ML confused

ML believes that MC was cheating on him but it was just the MC was getting blackmailed by some man

MC goes 'crazy' in the end and I think dies and ML? is veryyyyyyy upset that he got it all wrong and his lover never betrayed him

and that's it, please help me if you can ^^

 

Everyday fighting with the black-bellied male lead arc 2

 

I think it’s called “Everyday fighting with the black-bellied male lead”?

 

thanks <3

 

Whew that sounds so dark and angsty I probably shouldn't read it......
*Adds to reading list*