The lady, having discovered that she and her fiancee have the same sized ring-finger, is sliding her engagement ring back and forth between them, and making silly suggestive faces and noises while she does it. Her fiancee meanwhile is not really into it. The humor is likely intended to come from the cute faces and silly implication that sliding the ring back and forth could be considered somehow erotic.
The lady, having discovered that she and her fiancee have the same sized ring-finger, is sliding her engagement ring back and forth between them, and making silly suggestive faces and noises while she does it. Her fiancee meanwhile is not really into it. The humor is likely intended to come from the cute faces and silly implication that sliding the ring back and forth could be considered somehow erotic.