I think it takes maturity to respect that the rules are the rules, and regardless of the point of the thread, any discussion of sexual preference is against them.
The simplicity in that rule precludes any other matter if it being a joke or not, or how it should be taken, or anything like that. It's that simple. Just like political discussion is against the rules, so even jokes about politicians or politics that have no bearing on opinion isn't allowed. This really is black and white. That's why I marked the thread.