It is often said that in same-sex relationships that one partner often has a more masculine role and the other has a more feminine role. However, this is a common stereotype because only few couples actually go by this. It often shows that the person who is more noticeable homosexual is shown as the feminine role in guys, and in girls the masculine role. This stereotype is portrayed in the media when a gay couple is present, or so it seems. The first thing I think of when I hear this is the show Modern Family.
This can be shown in the television show Modern Family because it is said that Cam is more of a "mom" than Mitchell. This is playing off that stereotype for some humor. However, in this example it is only Mitchell who is conforming to the stereotype because Cam doesn't see himself as being more of a "mom" and as a result that is why he becomes so defensive when the kid asks him if he could throw him the ball.
Overall, this stereotype is just that, a stereotype. Most same-sex relationships don't define themselves by these different roles, even though the media most always chooses to portray them as such