>>64203804
Cass was never horny around you. She says "nothing will ever happen between us", unprompted. Like you don't even get the option to flirt with her before she blurts that out.

If you win the Hoover Dam battle with the NCR, she gets drunk and decides to fuck you, but can't find you, so she grabs some young NCR private and fucks him instead. This isn't really cucking since there's no option to romance her or even say you want to beforehand.