Score

As you swim with her, you suddenly realize somehow you're breathing under water, but your mind doesn't have the time to think about that (neither does your groin).

Despite having no legs you try to satisfy yourself and hold her big, plump bare breasts as you swim together.
The mermaid gets excited as she: -2

To the previous author: Try to think of the same way you can write your joke, without using offending words.
"I would if you had... the proper equipment."

That little pause in his words, as if he's embarrassed about what he's thinking, makes it even funnier.