Thanks everyone, I just hope it continues.
The only slight issue they're having, is they're both trying to be on the same swing at the same time - the actual swing in question varies, so I think it's more a wanting to be together than a favourite swing or position. Once on, they're okay but the second budgie landing is a tricky manoeuvre and frequently knocks off the first budgie
Luckily I'd previously ordered a double sized swing from the natural bird company as a Christmas present, which should arrive soon, so I guess they'll get that early and hopefully
they'll realise it's the sensible choice.