Brian seems to be very private about his sexual escapades.  We never hear him bragging about his conquests. The White Party was mostly anonymous.  Several thousands of guys come from all over the country to attend.  (More recently, White Parties have started in several major cities.)  a guy can go for five days of constant gay-sexual activities, totally anonymous, if so desired.  Ben, on the other hand, was collecting data and making observations for his research.  That doesn't mean he didn't fuck his brains out, but it was a great conversation starter and an academic reason to be there.  He probably didn't need anonymity to have a good time.