how anyone can be criticising the OP for being angry with the OW I seriously don't know
Do you know the song "Jolene"?
Many wives, in an attempt to save the marriage, blame the OW for the affair. If the wife can rationalise it to herself as the the fault of "the evil temptress who turned his head", she can pretend that he's a good man. Just like the singer in Jolene, she frames the affair as solely the OW's decision.
Believe me when I tell you that men can say no even to an amorous naked 19 year old woman climbing into their beds§. If they can say no then, they can say no to their secretaries, trainees, running club mates, you name it.
Men only have their heads turned if they want to turn them in the first place. Anger at the OW is understandable, but also misplaced.
§ And thank you to the two single male postdocs who (separately, I might add) demonstrated this to me, one of whom I'd previously shagged so it wasn't that he just didn't fancy me. You made me completely reconsider what men can be like about sex, for the better, and hold all of them to higher standards. Even if I was disappointed at the time...