[MENTION=7208]DiabolicalGenius[/MENTION];
Don't get my wrong my friend, I am a fan of NTR in all forms too, as long as excessive rape wasn't involved. For some reason rape just does not sit well with me but that is just a personal preference. As you mentioned that all NTR are good and I agree completely. Heck one of my absolute favorite titles called
Kashidashi Tsuma Marina is a full blown NTR-A and I love it. The only reason I prefer NTR-B over NTR-A is because of the satisfaction the player gets turning a woman from resenting you in the beginning to not be able to live without you in the end. That is a whole different high. So if NTR-B is a gold medalist, then NTR-A is a silver medalist but the difference isn't too much because a good NTR-A is definitely better than a badly written NTR-B.
As far as your scenario goes about earning money to pay the husband's debt off[unfair or not], I would MOSTLY consider the NTR more of a B instead of A. My theory is that even if she did volunteer to sell her body, if given an opportunity to earn money in some other fashion rather than sleeping with stranger(s), she would definitely back off because at this point her loyalty is wholeheartedly to the husband. The notion is pretty evident from the fact that she decided to let herself get violated for the sake of her husband and right now all that is on her mind is to help her spouse out. Of-course there is another theory as well if the parameters are different. If it is an unhappy marriage and the wife solely decides to fuck strangers for the sake of family and children then she wouldn't have much qualms riding someone else's junior. It will satisfy her not only financially but physically as well which I don't think she would mind. It is definitely NTR-A from start to finish in that case.