A hybrid of the phrase's filthy ninja, and filthy seagull (see definitions).
To perform a Filthy Ninja Seagull, you need cunning and the agility of a chimp(and male genitals).
The act of Filthy Ninja Seagull, is to (like a filthy ninja) sneak into a room of a
couple humping without bein seen or heard, climb on to the nearest wardrobe or chest of draws. Once this is done whop out your member and proceed to
masturbate. On reaching climax(providing you've not been caught) start to
screech like a demented seagull whilst spraying your man muck preferably over the couple whilst they're still at it. This now is where you need to be quicker than a leopard, and swifter than a er......... swift. Before the couple realise what has just taken place, or turn a light on you need to, to put it plainly, get the f@*k outta there without being seen. Thus leaving them wondering how the bloody
hell did a
bloody seagull get into the room.
To perform this act successfully
will instantly make you a LEGEND.
Example 1:
Master '' you have done well young grasshopper, you have successfully completed the Filthy Ninja Seagull task''.
Grasshopper "Thank you Master"
Master " However next time try using another couple other than your
parents"
Example 2:
As the
door closes and the squark of the seagull slowly fades away, Mike turns to Carol, both covered in the sneaky birds mess, and asks "how the
hell did a seagull get in here,it was like a bloody ninja"