Yea, both my twin and I have given each other rides.
Rule 1...and this is the only rule to tandem: the bike owner rides it, the guest is B*tch.
If you get hooted at, stand up on the bag and start screaming like "OH YEA BABY THIS MOTORCYCLE MAKES ME SO HOT" while humping his helmet. It's gets them all embarassed because then the situation becomes focused on them, and how they react to it. They usually shut up or they figure it out that with the big smiles and laughing that ensues that they were totally wrong and hopefully realize it isn't gay.
like most people said on the thread: F*ck em...who cares...you got the bike...they're walking or in traffic.