One mystery solved, then: Maneet had to take early leave so as to monitor my relatives on inbound flights to Gatwick 
My DP, displaying hitherto unsuspected levels of anal behaviour, is closely watching traffic reports etc. on their intended route.
He already confirmed it takes 30 mins less than they're allowing, and, assuming baggage reclaim is problem-free, they're likely to reach us not long after 8ish.
He also informs me that if necessary, we can leg it from front garden to back door within 3.5mins, (yes, he stopwatched it )
"...so make sure you're wearing the right shoes for running in..." FFS!
I sarcastically asked him if I should dig out my ski balaclava, too, to maintain a theme.
He looked thoughtful.
I assure you he's usually perfectly normal. His surname does begin with "H", though, it suddenly occurs to me 
Button,
"Marilyn, I said that about Jodie Velma on here but I think it got lost in all the comments everyone ignored me but I mainly think that as I can't believe someone could brown nose so much"
In that case, I will present you with a TedSpecial recognition award for first theorising re VelmaJodie way back on this thread, should the horrible prospect of her joining AC-12 prove to be the case.
Have a good one, everybody...see you on the other side. 