Dual relationships should be allowed when it comes to voting on debates. The reason is that a friend votes which debater made a stronger argument, without bias, for the purpose of giving constructive criticism for their friend.
Dual relationships should not be allowed when it comes to voting on debates. Because of the fact there is a multiple relationship, the voter is bound to have a bias in favor of their friend. They "could" provide constructive criticism, but they would still be voting for their friend.