The term can be used when speaking of beach parasols as well as umbrellas.
Origin : sexual fetish/punishment of German descent.
2. "This pornography movie would be vastly improved by the addition of a brolly-whopping scene."
3. "I fancy a brolly-whopping."
Can also be used as a threat, ie:
1. "Shut the hell up, lest I give you a brolly-whopping."