Are men with bigger penis more dominant ?

I would say yes. I did a lot of wives while their husbands watched because they had a small cock and the wife wanted to experience a larger cock. I’m not huge but 8.5x6”

 

Mine is about 5.4" and I am very dominant in bed. The two have nothing to do with each other. In my case it's the confidence of being able to really get women off and be a good fuck in general. A big dick is meaningless if you don't know how to fuck. (When I say fuck I'm including the whole event. Foreplay, making out, heavy petting, oral, intercourse... etc.)