It's not always from the same character, but it's always from the same battletag. When she ignores him the messages just get more and more frequent and he starts offering her weirder and weirder things (character boosts, race changes to whatever race he's fetishizing this week, mounts, etc).

We know about the ignore function, but I worry that if he messages her and it comes up 'player is ignoring you' he'll figure "her IRL husband is preventing us from talking, I need to go rescue her". He's said things to this effect before and figured out where we used to live based on googling our character names, which at the time were used in other social media as well.