I can't figure out if you can edit a post on this, so I have started a new one - sorry!
Just wanted to thank everyone for their brilliant advice and help. The OH looked in his bag of stuff left for him, came downstairs and thanked me with a slightlylongerthanusual kiss. Once we went to bed we had a very long conversation about sex without talking in metaphor (I don't think we have ever done this so frankly and openly before!)
To cut a very long (3 hour) story short, I got tied to the bed and punished for thinking such filthy things...
It went well, no?
Ps, Turns out our teenage 'outdoor' fumbles are his best sex memories, and would like to try something like that again soon...!