A posh wank, wherein a woman jerks you off whilst wearing an inverted ribbed condom (for your pleasure), and after ejaculation, she presents you with a cigarette and lights it for you.
Friend: "What did you get up to last night?"
Me: "Felt like like having a wank, so I got a bird over to give me a Posh Jonathon cos I was feelin' fancy."
"I didn't think the date was going anywhere, but I dropped her home and she gave me a Posh Jonathon so clearly it was better than expected."