Reason: Both the bouncing_breasts and bounce tags seem to implement the same thing. The bounce tag has many more posts than the bouncing_breasts tag, so I chose that one. However, I'm not against an implication instead (so the bounce tag can be used for other things that can bounce), but it would require a large cleanup of the bounce tag. Namely, finding every bounce image that depicts bouncing_breasts but doesn't have the tag, and adding it.
If we do the implication, then I propose another implication of bouncing_breasts -> breasts. The reason behind that is that I found about 10 bouncing_breasts images that didn't have the breasts tag, and it seemed silly that it wasn't there in the first place.
Updated by legga