Be good for a laugh, it made me chuckle when Nick posted it!
I spent the time driving from Cornwall up to South Wales Caving Club most weekends for a few years learning Welsh from cassette tapes, purely so I could eavesdrop on conversations in one of the local pubs, where the regulars switched to speaking Welsh every time we walked in. It was good for a laugh, as after about 6 months I felt confident enough to engage one of them at the bar, in conversation, in Welsh. The expression on his, and his mates, faces was a picture - you could see the cogs whirring around as they desperately tried to remember how rude they'd been about the English whilst we were in there...................