Motorcycle Riding Question

This goes out to those of you who are motorcycle enthusiasts....

I was listening to a radio show this morning on my drive into work and they had a caller that needed some relationship advice. Here is a summation of the situation:

• He is a young man, late 20s, who owns and rides a motorcycle (he didn't say what kind).
• He is dating a young woman who also owns and rides her own motorcycle.
• He things that she is "the one" not just because of their love of motorcycles.
• A couple of weekends ago they were out riding on just his motorcycle.
• When they stopped for lunch, somewhere along Highway 1, she asked to drive his bike and have him ride in back. He refused. Huge argument ensued to the point where she refused to get back on the bike and ended up calling a friend of hers to drive to where ever they were to get her.
• Two weeks later, they are still arguing because she thinks he is a neanderthal male who isn't man enough to ride behind a woman. He rides in a car while she is driving, so why not on a bike. He states that he agrees that he wouldn't ride in back of a woman because it just doesn't fit with the motorcycle rider mentality/man-code.

The radio show then opened the lines up and let people call in and give their thoughts. The majority of the callers agreed that it would just look weird to have the woman in front and the man behind, although one person did state that with the guy behind and his hands free then that would open up all sorts of opportunities. Some people brought up the safety issue that he is probably much larger than her and could she handle the bike with his added weight on the back but that was argued down by people saying that if she was a good rider then yes, she would be able to manage.

My thoughts are (and I admit it is a little old school) that I would think it would look odd to have a guy riding behind as well. And then one of the other voices in my head questions whether it is just because it was HIS bike and would he ride on the back of HERS?

Sadly, I had to turn off the radio before the discussion was complete, so I'd like to know what your thoughts, gentle reader, are on this topic. Is there an etiquette code on something like this?