Certainly, what you describe is not analogous to a weapon, because of the transfer of utility. The analogy fits better in a society where either 1) adultery is a huge disgrace to the offender, possibly involving punishment (the nuke only harms one side), or 2) adultery is a huge shame to both sides (the nuke harms everyone, like in the scenario posted). Though clearly not universal, the existence of this analogy is enough for me to call it "fun" ... Just in case you had any doubt, I surely do think this is a terrible view of marriage, for both societal and game theoretic reasons!