A sexy behind filled with a face or sperm. The object of desire (the person's bottom) becomes an arse sandwich only when one's face/ sperm is applied as filling. Yummy!
Man (on seeing a sexy arse): "I could stuff my face with some arse sandwich."
Pajama casual is a term used when working from home and preparing for a video conference. All business above the waist and your pajama pants down below.