I know this sounds dumb, but I don't know what the true answer is.

Ok, would I be related to my mothers, nephews wife's, brothers, son?

Sounds like riddle. In general the answer is no, BUT, if it's possible that there is a trick answer here. First the general case: your mother's nephew is your cousin. His wife's brother's son is his wife's nephew. So all this boils down to: your cousin's wife's nephew. Unless there is some blood connection between your cousin and his wife's brother (like if they are cousins, or the girl the wife's brother married is your relative), then the common name for the connection between you and the person in question is your "cousin by marriage once removed." But consider this: if your cousin married one of his cousins, it's possible that the cousin he married is your own sister. Then your sister's brother is you (or one of your brothers), and hence the person in question is your son (or your nephew). Or, if your cousin's wife's brother married your sister, then again his son is your nephew. Lots of possibilities here!

Your mother's nephew is your cousin. Your mother's nephew's wife is your cousin's wife. You are related to your cousin's wife only by marriage and nothing beyond that. There's no DNA shared between you (I could make a joke here and say, "unless you come from ___________", but that would not be nice).

You are not related to your mother's nephew's wife's brother (cousin's wife's brother).

You are not related to your mother's nephew's wife's brother son (cousin's wife's brother's son).

There are some legal things involving being related. For example, I am legally related to my wife, even though we are not related by blood (unless I were from ______ -- Oh cut it out!). I'm also legally related to my mother-in-law and her children even though we aren't related by blood. Of the considerations above, where I said you weren't related to them, you aren't related legally to them, either.

Hey you guys are good! I can even focus enough on this to figure it out. I was lost on mothers nephew being a cousin. Good job!