considering the average cuck will obey a woman half his size with no cock at all, the fact is that its 99% mental.
I have cucked men with larger cocks than mine a number of times.
many times they cum too early, or are just style-less dorks.
its easier if they are tiny cocked, but you would be surprised how even a big cocked guy will be cucked if his wife wants somebody else enough.
many women respond to attitude more than anything.
some chicks dig the smart rich stylish white dude.
but you either have it or you dont....