When your girlfriend / wife / female so is being a pain in the ass. Basically like you would call somebody who was being a pain in the ass a Twat. But this is saying they are being a Twat to the Max and really need to back off.
1. I was going to go out Friday and playpoker with the guys but my girl was all being Twaticus Maximus about us not having enough US time.
2. Your girlfriend is beyond a bitch, shes a twaticus maximus
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.
"Base we've got some square groupers floating outside of Miami harbor."