Are you an idiot who can't read? Get the fuck out of here with this "you should know to always use the bathroom beforehand" bullshit.

I had used the bathroom about 20 minutes before leaving, but with all the water I had to drink, about 15 minutes into the ride home I desperately needed to pee again.

She DID use it beforehand.

Do you have any idea how some people's bladders work? It doesn't fucking matter if she peed before she left, if she was drinking a lot of water it TAKES TIME FOR IT TO CATCH UP. I am the exact same way, if I'm drinking lots of water I will pee and then have to go again in the next 15 - 30 mins because my bladder is SMALL and as soon as it's emptied it starts filling up again with the next round.

You and her boyfriend clearly have no empathy for different people's needs. Or you're just woefully ignorant about how people's bodies work.

How would you feel if you had to take a huge burning painful dump but your partner wouldn't pull the fucking car over, because "oh you should have pooped before you left!" Well maybe, but doesn't change the fact that IN THAT MOMENT you need to fulfill a desperate biological need.

Next time, be assertive in your needs.

Oh because "begging her BF to pull over" is not assertive enough?