Edit: Note that I have no opinion here, just answering someone's request for a source.
A cursory Google reveals...
> Neither were Feynman's escapades limited to bars; more than one of his biographies have documented affairs with two married women, at least one of which caused him considerable problems.[0]
Charlie Munger seems to be a source for claims that he would sleep with the wives of his undergrad students[2].
And then there are these passages[1], which appear to be from his own autobiography. This isn't necessarily cheating, but assuming that what he's written is true, they serve to make the accusations of infidelity more plausible.
> "... You must disrespect the girls. Furthermore, the very first rule is, don’t buy a girl anything –– not even a package of cigarettes — until you’ve asked her if she’ll sleep with you, and you’re convinced that she will, and that she’s not lying.”
>I adopted the attitude that those bar girls are all bitches, that they aren’t worth anything, and all they’re in there for is to get you to buy them a drink, and they’re not going to give you a goddamn thing; I’m not going to be a gentleman to such worthless bitches, and so on. I learned it till it was automatic.
>I think to myself, “Typical bitch: he’s buying her drinks, and she’s inviting somebody else to the table.”
>I stop suddenly and I say to her, “You… are worse than a WHORE! ... You got me to buy these sandwiches, and what am I going to get for it? Nothing!”
This Baffler[3] piece also focuses on this subject...
>He worked and held meetings in strip clubs, and while a professor at Cal Tech, he drew naked portraits of his female students.
>Even worse, perhaps, he pretended to be an undergraduate student to deceive younger women into sleeping with him. His second wife accused him of abuse, citing multiple occasions when he’d fly into a blind rage if she interrupted him while he was working or playing his bongos.
We alway cut great minds a lot of slack. I have a mental experiment for this: imagine a man beats his wife. Terrible right? Now imagine the same man cures cancer. Well suddenly everyone is curious about the complexities of his marriage. That’s morality for most people.
It's interest balancing. If you do a lot of good, more evil is excusable in the mind of the average person. It doesn't make the bad things less bad, but it makes the person more human, as opposed to them being a virtuous angel, which nobody likes.
I don’t condone or defend anything he did, but following some of those links back, there seems to be a game of telephone, inflating the claims slightly each time. Munger for example seems to have said he was flirty with his students wives, but not actually sleeping with them. The nude drawings of students appears to have been in the context of an official art class, and not his students.
Regardless, this behavior was clearly inappropriate and should not be tolerated at a university. It does not appear to be actually criminal or predatory, unless I am still missing something.
It's worth including the conclusion Feyman makes in his autobiography about that episode:
> But no matter how effective the lesson was, I never really used it after that. I didn’t enjoy doing it that way. But it was interesting to know that things worked much differently from how I was brought up.
https://cirosantilli.com/feynman-was-a-huge-womanizer-during...