is this manhwa redflag? cheating?? or what?

Yea red fleg I‘d say but You’re prob used to worse ml‘s. Cheating idk they‘re f Buddies and he f‘s someone Else

Very juicy Smut tho

Idk I think it's fairly ok. At most yellow flag. I mean correct me if I'm wrong anyone, but I don't remember any specific instances of anything nonconsensual. They're fuckbuddies but they're both into it, and the ML breaks off with his past fuckbuddy when he officially starts this thing with the MC. He's not fucking anyone else at the same time (other than I think once after their initial one night stand, but at that point, he didn't even know who the MC was, and probably thought he may never see him again). People are just hard on the ML because they don't like a ML who has slept around, even if it was all consensual.