I posted something similar a bit earlier and ended up trying this out.
You get a very very small (less than 100 renders id guess) catch up that mostly shows what I assume was "big incident" before the end of the first game. You dont really get to know the characters or how you started banging them (beyond a line or two), and characters start referencing stuff from the first game from the get go.
Id say I (as a story comes first kind of person) was pretty disappointed by the "story" here so far. You (seemingly) are already fucking all the relevant characters so there is not much connective stuff between scenes (mom and son go to work, work day happens, mom and son fuck in office because porn, you get home sister wants to fuck but mom interrupts, you talk to mom then go bang sister and that's where i dropped it)
Honestly the whole "issue" here is about as logical as most NTR issues. The relationship(s) are all kept secret (I guess?) despite the fact that MC and his cousins are talking about how they are dating like a couple of feet away from the mom (who doesnt know) on a quiet street with nobody on it but she didnt hear it because........ well the story hasnt gotten to that point yet
oh not to mention every room in whatever house they moved into having soundproof walls and stuff because porn games have to have comical amounts of moans.
I went ahead and looked at some of your "top games" and I would say this might suffice as porn for you (it doesnt for me) but it wont scratch that compelling story itch.