So that you can drink while you ride, you might consider something like the Camelbak system. I don't like reaching for waterbottles either; but this tube thing on my shoulder, it's great, i can work it with my mouth and drink whenever i need to.

Jiffer
And There's no way on earth that I could ride a century without stopping to go to the toilet. I know some men can urinate while on the bike, but there's no way I"M going to do that either.

YOu didn't mention how many hours your BF took to do that century; but the fact is, if you don't urinate for 4 or 5 hours and you are really exerting yourself, you stand the chance of getting kidney stones from dehydration. It doesn't sound like a good thing to me.
Maybe I overhydrate; but the last thing I want to do is deal with dehydration on a long ride.