Very nice! Nothing better than a little teaser at the end...
Not sure if I'm in the the minority here, but I actually found the "side stories" more interesting than the "main rivalry" between Sarah and Karen. So I for one am not the least bit miffed by the fact it looks like that particular pecking order has been firmly established (for now, at least), and the young MILFs will be bumping tits with some other challengers in the near future.
Sarah's match against the two hooter babes was very entertaining - though as per usual, I wouldn't mind it if the action sequences were a tad longer and more detailed, especially when it comes to the morphing, compression and displacement of the two warring masses of titflesh...
I do realize that my own stories tend to go overboard with too-elaborate and overly long-winded descriptions, but I reckon delving a bit deeper into the minutiae wouldn't hurt here. For example, that close and intimate bearhug boob-grinding duel at the end of that encounter was practically begging to be fleshed out in greater detail; Sarah's slightly smaller orbs slowly but surely starting to take over the space between their busts as Ashtyn's once-perfect but now tender and softening, more and more obviously outmatched college-aged boobs begin to flatten against her chest. The stunned redhead staring on in horrified disbelief how the older woman's best assets simply keep pressing forward, displacing her usually so dense and firm flesh, causing it to splay out and simply ooze around the MILF's better, stronger tits... 
Anyhow, it was very fun to see the curvaceous blonde 30-year-old (?) managing to pummel both busty young hooter girls flat, one after the other, with Sarah's greater experience and her big, meaty jugs' obviously very resilient inner tissue proving too much for even the redhead's seemingly nicer (i.e. a hint larger and rounder) pair to handle! Hopefully the 18yo high school girl Denise will be able to put up a better fight - or maybe bring a couple of her friends along, lol! Teen boobs vs. mature mammaries is always a great combo! And speaking of mature mammaries, the chesty 50yo Theresa will no doubt provide additional variety quite nicely! I do appreciate you including so many different body types and ages in the mix... With a bit of luck, we might even get to see a Theresa vs. HS teen or college hooter girl showdown at some point!
A great continuation of the story, with lots of potential for further developments!
Brylee, Ashtyn, and Olivia were all canon fodder for the two main characters, and I hit 13,380 words as it was, so skimping on those details was on purpose.
On a hopefully positive note, I've already got 3 fights in mind for Sarah and 1 for Karen once she gets over the humiliation of losing this one. It shouldn't take 14 months between stories this time as this was the fulcrum for everything that could come later and I wanted to get it as close to my original vision as I could, while everything following should be much easier to get written out.