[ElProximo]

Ehh.. well he is quiet for the reason he doesn't want to get challenged by Isaac in any sort of man-to-man confrontation,
and,
he does have to see what pans out,
and,
in fact, when the last boyfriend came in - they did so knowing that Karly was minutes away from eviction.
I would suggest that this actually does hurt Noirin and if I was Marcus I would just try and 'disappear' and actually just let as maximum drama happen around her and this business.

I would say 'gentleman' behavior is easily the least likely thing Marcus is doing here.