Doesn't this "avid cyclist" know how to draft? My spouse used to cruise the flats at 28 mph. No way could I even come close to that speed on my own, but we rode hundreds of thousands of miles together at his pace with me on his wheel. He had to back off on hills, but he would just make up for it on the next flat stretch.

It is possible that you're not going fast enough for there to be much of a draft. It is also possible that one or both of you are too squirrelly to be part of a pace line. That's fairly easily fixed. Just buy some rollers (the kind without the bumpers on the side) and you'll be a good wheel in no time.