The reason for being so explicit about everything is probably just to establish the cause for the legacy. If he had other potential heirs, there's a chance that they would contest the will if there was no reason given for the legacy. The important thing about wills is to make the intent clear, and it's very usual for causes of legacies to be cited like "out of natural affection" and "my loving brother in law." If there's a relationship, to a legatee, it's important to say what it is. Given the terminology he uses, it sounds like he had some legal education or used a decent lawyer, so it's probably not in there just to stir the pot or anything. Well, if the first one was born in 1786, Lebleu was 64 at the time. With a 27 year age difference, it's probably not a love-marriage.