i dont think NTR since it is consensual more like a brake up and another get together like going from contractual to an emotional marriage (example not whats happening here)Either bro is into NTR or he's the most wholesome MF in the world for looking out for Haruka's happiness.
Or both.
honestly i think this is more of a polyamory thing since the husband is for it. def not NTR or cheating since he's into it.i dont think NTR since it is consensual more like a brake up and another get together like going from contractual to an emotional marriage (example not whats happening here)