Did for me, but it's not the standard story. A year or so ago, an old friend I'd known for years and years and years moved back into town. At the time I was fooling myself that I could handle then-DP's abusive tendencies. Mostly by calmly and patiently pointing out that making a massive production number out of things, and particularly by being aggressive and nasty toward anyone she suspected of wanting to be OW, wasn't helpful.
Anyway, I'm not having a good time most of last year. Three funerals in six months, two of them very, very dear to me. Fourth funeral getting ready to happen to the nearest to a real mum I ever had, and I'm looking after her in the final stages of dementia, off work, carers' allowance so I don't exhaust all my savings, etc.
Ex-P convinces herself that this is not sufficient to explain me being a mopey, miserable bugger with no money and fixes on old friend as the likely OW. Full disclosure, I hit on old friend about ten years ago, she expressed a disinterest in dating, end of subject as far as I'm concerned, sure she's getting divorced at the mo, but I know she's not into me and we'd got to be friends.
Ex-P doesn't know this and rather than asking me, because she knows that ii get snotty about her being paranoid, gets into a weird, stalkery one-sided EA with old friend - late night heart-pouring, earnest discussions etc. Up to my elbows in elderly relative incontinence, getting woken at three in the morning while she rants about angels, all the rest, I notice NOTHING.
Ex-P is, meanwhile, interpreting EVERYTHING as confirmation of her theory that old friend is going to Steal Her Man. (Thinking of me as property, had I known, would have been a dumping offence right there.) It comes to a head with a massive row during which I learn about the long, late night chats I was supposed to be, and she was actually having with old friend. And she'd actually threatened the poor woman, mid divorce, with hurting her children. With the classic bully/abuser's excuse of 'I was just joking'. Offered her the choice of apologising for her behaviour or being dumped, and she told me I couldn't dump her, she was dumping me.
Anyway, hanging out with friends, end up discussing this with old friend and 'what was all that about?' conversations happen. Couple of weeks later, I injure myself embarrassingly (flareup of old trouble) and she is kind enough to see I get to a&E safely. This is where - with me out of my gourd on morphine and gas and air, apparently I am adorable while high as a kite - The Spark happens. We've been together a hair over six months now, and it's going great.
So, yeah, real love can result from an affair. Just not necessarily between the parties thereto.