Originally Posted by Arrowbound
Now you know where you stand and how she views the relationship. If it doesn't sit right, it just doesn't. You don't have any obligations to go any deeper or further.
IMO, there can only be any cheating to speak of after
the boundaries conversation and when those are broken w/o consent. Everything else just sounds like an undisclosed, one-sided expectation.
If someone wants exclusivity or expects me to be single during our first encounter, then I would assume the boundaries conversation should happen prior to sex. The responsibility for bringing it up laying upon the party who wished for exclusivity in the first place. Btw, I think boundaries conversations are a total turn on.
That being said, if you like someone, that can be a real bummer. The original post sounds more like a case of unrequited feelings than cheating. I am sorry that it happened. I would categorize what happened there as casual sex.