[Shoujo Tetsugaku (Ariatorai)] The Emotionless Childhood Friend Was Taken by a Creepy Otaku and They Were Having Looney Lovey-Dovey Tongue-Kissing Sex 2 [English]
This is hardly "ntr" at this point. They're just a normal happy couple, and there just happens to be a random loser on the side who didn't take his shot and is now whining about it.
This is clearly BSS, a subgenre of NTR. Fucking idiots claiming shit like this is "vanilla" when its clearly not lmao. Like there is a "cuck/incel" aspect to this.