Years ago I was using Zoosk on Facebook. I spotted a local man who looked interesting, messaged him and he suggested we meet for a date. I went looking for his profile on Facebook and lo and behold, no relationship info, but plenty of public photos showing a woman with him. Found her profile easily enough, and stating she was married to this person, and lots of photos of them together. And children, albeit adult ones. I emailed him again and said WTF, you're married and on a dating site as single, is this a joke? He replied "If you don't mind, then I don't mind" and when I said well what about your wife, he replied "Well she doesn't need to know, OBVIOUSLY" WHAT a jerk!
So guess what I did? I screenshotted the LOT and emailed his wife, apologised for upsetting her in advance, but that she needed to know that her husband was planning to cheat. She verbally abused me, threatened me and accused me of being an unhinged psycho. So clearly in denial, but I decided I did the right thing. I actually discussed this with a couple of friends, one said I should never have told her and that I may have destroyed a marriage. The men or women who step outside their committed relationships are the ones responsible!!
Anyway, I guess the point of my ramble is maybe don't discount this, but keep stumm for now and do some more digging. No smoke without fire isn't always true, but I would "stay frosty"....