Alright /bant/, I've done some math and have an important message to all.

According to Wikipedia, the average length of a penis varies from 5.1 to 5.9 inches. I went for a safe 5.5 inches for an average. The average radius from the core center of the penis to the skin on the outside is .75 inches. From this we can roughly find the volume with pi timed radius squared times height. This comes around as the average penis being around 9.72 cubic inches
Next I found the volume of the average human adult male. I had to first find the weight, which according to Alex Schlessingerman's "The Physics Factbook" is 70kg or 154 pounds. Weight is found by multiplying an object mass by the force of gravity, 9.81 meters per second. After taking gravity out of the equation, the average mass of an adult human male is 7.14 kg. I then found the volume by dividing this number by the average density of a human, according to Wikipedia, 985 kg per meter cubed. The volume of the adult male was then found to be .0072516316 cubic meters.
Utilizing the volume of the average penis I found earlier, 9.72 in cubed, I get .0001592828 meters cubed. This means the penis is 2.19% of an adult male's volume.Assuming a lack of testosterone or female hormones makes the person a female, balls ignored for ease, fucking a trap is only 2.19% homosexual.