I always thought winking was one of the more innocent gestures!
I wonder which is the least used one? My guess would be "proposed", which suggests wedding bells. Can you imagine a less romantic way to do it? "Oh, my husband proposed by sending me a gesture on EP. I later discovered he was having finger trouble, but he was too embarrassed to say so - after I'd excitedly sent an EP card to all my circle, telling them the happy news."