At the moment my dream bike is the Circe Morpheus tandem. My better half started having balance problems a few years ago and had to give up riding after a long lifetime of cycling. He gets bored riding on a trainer indoors and wishes he could join me. In the front recumbent seat of the Morpheus, he would have a low center of gravity and a clear view. Unfortunately, the price is a bit more than we can afford, between currency exchange rates, shipping, and import duties.

https://www.circecycles.com/products/morpheus/