I found the opposite of this to be true. Although not married, been together for years

We also went through a stage of not being allowed to take photos of her, then i was, and now i'm not again unless on holiday or at a wedding or something
I don't think the OP wanted to buy another camera to take with him, he wanted advice on taking 2 of his existing cameras. He already has some excellent equipment, i'm sure he doesn't need to spend £1000 to save some weight off one of his bodies, especially as he hasn't actually quibbed about the weight, more the security.
Shayne, if you're happy carrying 2 bodies then go for it i say. If last time you were annoyed about missing shots through lens changes etc then i think you know the solution, 2 bodies or a different setup of lenses although i'd argue why spend all that money on ace lenses to not take them on a photography trip? (you don't mention if you have any others that may be more suitable) Putting a camera in a bag may secure it whilst not in use, but you have to factor in whether taking it out of the bag will make you miss your shot in the same way as swapping lenses.
Cracking shots from last time by the way, i can see why you'd want your best gear with you to capture it all