When did we start downplaying cheating to just being an "overlap"

I guess nowadays cheating is just called overlapping? I do nails and I have heard 3 different women use the term "overlap". One girl was telling me about her new boyfriend and giggled while saying "Yeah there was a bit of an overlap". Or one of my clients is dating again after her divorce. Actually not AFTER because She said there may have been an overlap on both sides. So.... You both cheated on your partners. I see it all the time online where people will say there was an overlap and it downplayed to this "cute" thing when cheating isn't cute. Why have we stopped calling it what it is.

Edit: No. These people aren't talking about entertaining people. They're talking about their old full blown relationship overlapping with their new full blown relationship.

@Ashley they left their spouses for each other but said there was some overlap on both sides. Since overlapping is used in place of cheating I'm pretty sure she just meant they both cheated. Even if they didn't physically if they left their spouses for each other there was at least emotional cheating