[Idiom] I want a pizza dat ass

[Kengo]

Hi people,

An American friend of mine (female) jokingly told me to say "I want a pizza dat ass" to my girlfriend.
I find lots of sloth memes with this online but I don't understand what the caption means and have no clue what it'd imply if I said that to my girlfriend.

Any help would be appreciated.

 

[Rover_KE]

It's a (sort of) phonetic rendering of 'I want a piece of that ass (BE arse)', which appears to be a way of requesting sexual intimacy in some circles.

I don't think I know your girlfriend, so I can't say how she'd react.

Rover

 

[Kengo]

It's a (sort of) phonetic rendering of 'I want a piece of that ass (BE arse)', which appears to be a way of requesting sexual intimacy in some circles.

I don't think I know your girlfriend, so I can't say how she'd react.

Rover

I did think that it might be a rhyme but couldn't think of anything that would fit. Still don't understand how it's meant to be funny but all clear now. Thank you.