That's fabulous video footage LES..
Similar to what I managed to capture a while back at the shop:
http://forums.loaches.com/viewtopic.php?t=6295
I see this sort of behaviour from time to time in my river tank, but it's never looked quite the same as the footage from the shop. What I mean by this is that the female tends to be showing a lot of aggression towards the male, rather than it appearing 'tender'. The females are also very feisty towards my
Sewellia lineolata, which is an ongoing thing, as they all like the cobbles just in front of the intake sponges and want to claim them as their own.
I can't wait to get the new tank for them, although this may be slightly delayed due to a certain someone not ordering the tank this week like I asked!

But it should be here within a couple of weeks, and I'm hoping it will give the hillies a lot more of a footprint so that squabbles lessen a little.
Emma