Waow, this sounds like a wonderful story, only beginning
. Like any second date, don't go too fast as to for example buying a tandem (like you wouldn't buy a restaurant because the service during a first date was lousy
). Maybe try to find another rental place, better go to an LBS who specialize on tandems good tandems and see if they would rent you one, talk to them about the date.. no matter what the rental fee is gonna be.
Maybe later you'll buy a tandem. And even ad a tag-along to it
Ps; don't worry too much about the voice warnings, I bet she can read your mind.