Pregnant Submarine

Okay, listen up, smarty-pants. You see, a submarine is a ship that goes underwater, right? And a pregnant woman has a baby inside her. So, get this, it's like she's a "sub-marine" 'cause she's got a little marine (sea creature, get it?) inside her, under the water. It's wordplay, you wouldn't understand. This is high-level humor for big-brained bears, not for smooth-brained chuckleheads like yourself.