Oh how gorgeous they both are
As you say it's early days so I'd keep an eye and don't allow things to become too aggressive as Lily is so much smaller than Nando. It's always difficult until they find their place in the pecking order.
I won't be surprised to hear that Lily eventually comes out as TopCat
The jumping on back and biting neck can also be a dominance thing I understand but at Nando's age I'm sure he doesn't know why he's doing it either
I think I would try and distract him by playing with them both. Fishing rod toys are always good for this. Have you visited the Purrs Shop yet? Profits go to cat rescue. Just click up in top right hand corner. Da Bird is a
great favourite and is sure to distract Nando.
Glad to hear Lily is starting to fight back. Our Billy (neutered in 2004) still does this occasionally to Ruby (who had her op last year) but then Ruby is such a big softy.
The Feliway takes a few weeks to kick in but should help when it does.
ETA the link to pics of Purrs cats playing with Da Bird. Sorry couldn't resist. Just click on link and then click on next button below pics
Our Noni is the beautiful furry tabby flying through the air in the garden
http://www.purrsinourhearts.co.uk/catalog/da-bird-uk-gocat-da-bird-cat-toy-part-easy-store-rod-p-38.html