As a bisexual, I'm constantly amazed by this phenomenon. Every time a straight couple walks into the bar, the woman is always at least 20% hotter than the man (that statistic is figurative, obviously not real). Often it comes makes the difference in "I would sleep with her, not him." This isnt true of single people at the bar, where it's more 50/50.

This would seem to violate the TRP understanding of how women date.

For context, the social scene I'm calling "the bar" is mostly mid-20s, leftist, queer-friendly middle class hipsters with decent jobs. I'm sure this varies along different socioeconomic conditions.