Really depends on their 'relationship' doesn't it as no one really knows who either of them are . I think this was in london, london is a mecca for dominatrix's, fetish clubs also ,that the rich and powerful use, it could well be this guy paid for this service ,in that he gets off on public humiliation.I don't see how that makes him a 'simp', a freak yes, but then many of us have all sorts of perversions, I contend he isn't a simp in this case because he is essentially paying for a service and doing what is called 'topping from the bottom' in fetish speak,in that he is dictating how he wants to be humiliated,how long for and what she can and can't do ,there is probably a 'safe word' as well so he can't stop this at any moment . All sorts of powerful men get off on this.
However ,if this wasn't a paid service to some corporate freak, but this is this guys wife doing this and he is being 'punished' for cheating on her , or he is doing this for some absurd 'social experiment' for a university no doubt run by feminists and homosexuals , in my view he is simp of the year or maybe the week, plenty of men would seriously lower themselves for p*ssy end of the day.