I work with elderly people and I've noticed couples that have been together for decades tend to have some quirks that they both do, they kind of take after each other in mannerisms. One couple I met laughed the exact same way for example, head back and with the same kind of “melody”. Another couple sat the same way whenever they were both sitting down with their hands in their laps and their feet crossed at the ankles. Some couples just have small things they do the same as how they handle a knife and fork, how they say certain words or the way they move. I think Joe and Nicky must have some things like that and would to read about it from Nile's pov.