At the end, when Lucy and Ethel go to see the men, who are behind bars, Lucy first kisses Ricky, then Ethel steps up to kiss Fred. Their lips/faces very clearly never get close enough to actually kiss. It's well-known that the two actors, Vivian Vance and William Frawley, couldn't stand each other.
The stack of plates Lucy drops on the floor are very clearly all attached to one another based on how the stack moves and falls.