A Question of Conscience

My mom and I went grocery shopping on Wednesday (big mistake going on the first of the month).  While we were there one of the employees was stocking up a soda display and dropped a 12-pack of soda and broke it.  My mom told me and also said that the kid said, "Shhhhhh----," without actually saying the word.  Mom did say that he cussed (she didn't really care), but I asked if he actually said the word, shit.  No, he didn't, but it was his intent to say that word.  I asked her if I stubbed my toe and simply said, "Ffffffff---," does that constitute the f-word even though I didn't actually say it.  She said, yes it does, because my original intent was say the f-word.  So, if it is merely intent and no actual cuss word is spoken, is it still considered cussing?  Please support your answer.