I don’t know what to tell you. The problem is it’s hard for me to give satisfying answers without spoilers. Outside of the couple people here, the responses I’ve gotten have been quite the opposite. So I’m going to go get some work done. Thank you for caring enough to share your opinion.
This is just my opinion of course, but I believe it's not really a case of missing context or anything like that. Well, I certainly won't deny I'm sure some cases will be that

IMO it's more that your story had the potential to go several ways, and a decent handful of people expected/wanted it to focus more on the netorare part. You did not go that route, and you were under no obligation to do so, but some people will naturally be disappointed if it doesn't go the way they would've preferred.
I know and recall about the dinner thing in terms of future jealousy, so there is some potential there—however a lot of the netorare potential was basically cut off or had its possible impact lessened with the more or less swinging-ish route you went.
Obviously some people are seriously lacking when it comes to them constructively stating as much, but poorly/rudely worded feedback aside, they're not wrong for feeling that way. It's not like there aren't plenty people who were fine with the way things went as well.
So I believe the mixed reception is more about expectations/wants not being met (which isn't your fault, you do whatever you want with your story) but I still understand the disappointment if people were digging the netorare. From many angles depending on many viewpoints and opinions, the netorare is lessened because Jake gets action (especially when it's at the same time as our protagonist), and the cheating is already out in the open and was accepted from both sides (
not telling him she has a dick aside).
Personally my opinion is a bit mixed because I don't dislike the route it went, but I was greatly enjoying the netorare stuff and as such will be holding onto
the previously mentioned fact that they did not tell Jake about her dick.