As a brief introduction I am a 39M who has been married for almost 18 years to a beautiful wife with tiny breasts. While I remind her that anything more than a handful is just a waste, she is very sensitive about her small chest, especially since her sisters are so well endowed. Despite being almost 40 my wife has kept herself pretty tight and is still slender with a flat stomach. Her sisters, however, have both let it go a bit and are a bit overweight.
The sister in this story still has a pretty face, but is fairly overweight, probably your average MILF. She would still be fairly attractive, especially if she wore clothes that were new or actually fit her. Her marriage is on the rocks and she is contemplating a divorce which probably let up to the circumstances of yesterday. With Covid she recently decided to move her older kid into the online school my kids go to. Every Friday they have an activity so the students can socialize. So she brought her kids over to my house yesterday while I was working from home and my wife took all but the 3 youngest to the activity for a few hours.