To do the dirty on someone means, in Australian and British English,
to behave unfairly or very badly towards someone, often without them knowing. And then he did the dirty on her and went and had an affair with her best friend.
— The free dictionary
which I think is a pretty cool and useful idiom. However, it seems it isn't used in American English, so what would be the AmE version?
IOW, how would you rephrase the sentence above so that it sounds idiomatic in AmE?:
And then he _____ (her) and went and had an affair with her best friend.