Yes, they can, under the following conditions:
- One of them is absolutely gay, so there is zero chance of attraction.
- At least one of them is being delusional that 'they are just platonic friends'.
- At least one of them is not aware - like you stated in the question, you were fine with her talking about her escapades, and you were fine and you thought she was, until she indicated how she really felt upon seeing you with someone else.
- The two are relatives, and even this has been proven wrong enough times
Other than that, NO, not really.