Don't worry, the author got a fuck ton of back lash for this horse shit in the novel and back pedals super hard.
Eh, while I can understand why people would be pissed the MC would be loosing the MILF, but it does make more sense for her to be allowed to move on and find a more stable father for her daughter. Now before you break out the pitchforks, hear me out.
We all know how this kind of a story turns out. To many women, and the author struggling to give them all some screen time. So there are some benefits to giving the widowed MILF a happy send off with the MC's blessing.
It makes the fact the MC is banging so many women less awkward and allows the MILF and her daughter to play an active role in the story, just not one that creates yet another jealous jilted lover the MC has to pacify.
It also allows not only for those left to get more attention, but also adds the potential for a POV scene with the happy new couple. So in the end the MC can tick the MILF slot on his punch card, keep his harem manageable size And most importantly of all, help keep the jealousy drama to a dull roar, rather then the screaming fits that just bring down the mood.