Threaten

Someone just walked over and asked me "Did you mess up with my friend?" during lunch hour, Date 20070403 and Hour 1310. Can we call this a threat? May be I should file a police report on this...
Someone just does not ask a friend to threaten me like this, this is not the way. If someone does not like me, just tell me and we can sort this out the other way but not by telling someone else and let the someone else threaten me...
I know I joke a lot but I always tell out my words with a smile and that means big jokes. May be some people does not like that. I remember joking around and a friend told me he did not like that so I sort of keep it serious with him after that...
But this time...