Enjoying a meal or snack, while sitting atop the toilet. Done most often while defecating.
I was pressed for time between work and school, so I had to have a gentleman's lunch.
A meal taken in private while evading responsibility and perusing pornography
or other sexually explicit material
Bento bow from Sushi King, the lesbian scene from Mulholland Drive: time for Gentleman's Lunch!
Having sex with a daughter and mum in the same night. It does not have to be at the same time. Walking from the daughters room into the mums room is generally where it starts.
I had sex with my girlfriend and her mum asked if I would pleasure her after I was finished. I had a gentlemans lunch :)