''I wish that girl would have gotten dirty.''
really? you think iot would be fair to have the girl sit in her underwear in a car with three dressed guys?
not gonna happen, dude.
your friend's brother would have made her go behind some bushes to take off her muddy pants and then made YOU take off your pants for her to wear.
be careful of what you wish for.
If you're not embarrassed to wear briefs 95% of the time, why were you embarrassed that day? you could have been naked dimwhit.
O big deal; people wear a lot less to many public beaches.
Rather than taking your pants off didn't you have a boot liner, towel, newspaper, plastic bag or other such item to keep your brother's seat clean? Certainly on a fishing trip you usually take that sort of stuff with you (a boot liner at least) and that would have solved the problem.
From the Kiwi