I also love being corrected, I guess that you have to try and judge how the other person feels about it.
I would never try to correct a French persons English in France unless they specifically asked me to, but over 8 years I there have probably only been 2 or 3 occasions when people have tried speaking English apart from when they are drunk and just dribble out n'importe quoi.
In England is someone is there to learn the language then I will but I follow Bettys rule, only if I dont understand or if someone else might misunderstand, I had my friends daughter stay about 10 years ago, she was then studying to be an English teacher, thankfully she gave it up as she would have been a real garce, I found her a well paid summer job, gave her free board and lodgings, ferried her around lots and generally was on hand to cope with her mood swings and tantrums as she was at the time a troubled teenager, my friend who gave her the job said never ever ask me to do anything like that again Chancer!
Anyway one day I asked her if she liked something it was a foodstuff cant recall what, she gave me a withering look and said "naturally!" in a disdainfull tone as if I should have known, only a moron like me would ask the question,so I served it up. She said "I tell you I dont like this!!!!" so I said "I thought you said you did" "No!" she replied, "I said NATURALLY!!!" nat reely = not really
I explained that she should watch her prononciation on that one or she would be misunderstood by others and she flipped an said "Well I can tell you that you speak French crap!!!"
The other correction I tried and failed with was her spoken use of moreover instead of also.
I dont take risks now, even if someone is always asking me how to say something I dont assume that they will be happy for me to correct them, but I like Sweet17 am delighted on the rare occasions when someone does.