Originally Posted by kane

There is a very easy way to know.

Have your friend build a paper mache volcano. Once he has a it done you have him put a container of vinegar that he has put red food coloring in inside the volcano. He will then drop baking soda into the top of the volcano. When it hits the vinegar it will cause an "eruption." If, while the volcano is erupting, you are sucking his cock then you are gay.