Why was that hug so weird??

Watching last night's episode with Emma and Caspar - why was figuring out a hug SOO freaking weird(especially for Emma, Asparagus knew) after they had BOTH literally JUST hugged Charlene completely naturally without a SINGLE issue?!?

I love both Emma and Caspar(saw their wedding but only really tuned back in last week) and I find them absolutely fascinating to watch but I know it's a slightly perverse curiosity of seeing just how WEIRD they are!!!