I find the mouth to be much more versatile, so mouth it is.

Two thumbs in reciprocating movement.

It depends on the country and possibly also where in that country. Fairly common in my experience in the Netherlands, Germany, Austria, and Switzerland, and maybe the Scandy countries where you often get two mattresses instead of a single double. I don’t recall ever having seen them in the UK or Ireland, and in France, they’re more of the exception than the rule.

You’re not wrong!

Getting a cold butt when your other half pulls the quilt to their side.

Not systematically, it very much depends on how the selfie is presented. If you are overtly seeking sexual attention, then yes, probably, but if not, then no. The days when I can imagine I’d be attractive to women much younger than myself are well and truly over.

Black, because it matches your shoes. The silver is more revealing and sexier, shows off more of that gorgeous body, but harder to match with shoes.

Bottom left looks cute.

Left hand end

2nd from the left

The one in the middle.

Go for the middle.