Can I choose whether I want to have NTR or not? Or do I have to make choices to avoid it?
As far as I know, the only confirmed NTR is with Teodora.
Because with the girl that James cheats on his partner, technically it wouldn't be NTR... since she decides to enter your harem and becomes your sex slave, not a girlfriend as such. But she's not James' girlfriend either, she's more of a lover for him after meeting Emma.