The act of two peoplemaking out with such fervor that it is audible to others around.
Example 1:
(Josh and Lana are making out)
Marlee: Can you hear that?
Amanda: Is that the fish tank?
Example 2:
(Alexander and Kayla were making out the previous night)
Alexander: (sly look) So, I kept hearing a belt buckle last night...
Nathan: Yeah well, I heard you fishtankin' it up! How about that?
Alexander: (holds head down in shame)
Nathan: (ultimate glory)
When it is late at night (around 3am) and your intoxicants have worn off, and you are just a shell wandering or staring aimlessly at walls, like a fish in a tank. Also, to actually fishtank you cannot be aware you are doing it -- that would mean you're coherent.
Fashion forward fishing. The art of modeling runway attire under the guise of fishing without looking anything like a dirty fisher person. Usually requires a costume change after getting a splash of water or 7 minutes.
I wanted to go to the beach today but my fishanista friend Cathi is at home glittering her Crocs and packing her Coach rain boots so she can fish with Bobby tomorrow.