How funny that you should post this today! I noticed a big flub in the Homecoming episode I watched recently that I had never noticed before. I knew next time I stopped by the Lounge I wanted to share it with people who would get a kick out of it, too -- fellow Lucy fans!
During the party scene Lucy is wearing her Don Loper dress & she has accessorized it with a belt with a sparkly square buckle. Ricky pushes his way through the crowd at the front door, & somehow he must have torn Lucy's buckle off. I assume it ended up in his hand because I can hear her say,(& this must have been an ad-lib) "That's mine, dear." I watched her surreptitiously try to reattach it a few times with no luck. You can tell by the way her hand is curled that she is holding it & hiding it from view.
Eventually she either gets it back on herself or they stopped filming for a bit to do so. When she turns from the door & walks a few steps back into the living room it is in place again.