no ntr is not chucking at all cucking is when the person is fine and gets off to someone else sleeping with and "stealing their partner" , the big actual differentiation is that circumstances don't really matter with NTR so long as it hits on that core of someone being upset over a girl's affections being "stolen" from them by someone else (or even more generally just focused elsewhere). cucking isnt cheating its a kink and mutual with both parties.