This is not a happy ending hentai if that is what you are looking for. IT is definitely NTR. That being said there are scenes of the mother and son together if that is what you are looking for, but (not trying to spoil anything) it is still an NTR moment even when they are together. And some of those sex scenes aren't what I was expecting but still surprisingly good. It is probably worse than most NTR if that genre isn't for you. The son here had real chances to change things but apparently didn't have the guts.And by the second OVA the mom and the new guy are really rubbing his face in it.

If you want a happy son / mom hentai story then look elsewhere. If you are just looking for good sex scenes and can look past the story then give it a try.