[ Ah... it's in those situations where you have to force your biggest smiles. Athena knows that feeling all too well. Though at least her smile isn't murderous and she doesn't look like she could kill twenty-thousand puppies. ]

I've got it!

You should try practising in front of a mirror. What makes a smile look happy are your eyes. [ She nods sagely. ] If they're gentle, then you'll be able to convey your message properly, even without the corners of your mouth being turned up.