"Eskited" about "misking" up some "Mescican"...

Although the boys have been home almost 2 years (Yeah.  I'm not kidding.), we still have trouble with some letters and sounds.  Specifically, the letter "x".  For some reason both boys have trouble with some words that have the letter "x".  For example, mixing or excited or Mexican.  Which come out like misking, eskited and Mescican.

The whole thing started after we overheard Charlie telling Sam he was "eskited" about....well, I don't remember what...just that he was "eskited".  After eavesdropping for a few minutes on the x-challenged conversation, we tried to help him correct his pronunciation.  Funny thing is, he can say fox, six, ax and several other short x-words, but can't get the word mix to come out right...

Kenny:  "Repeat after me:  six."
Charlie:  "Six."

Kenny:  "Six."
Charlie: "Six."

Kenny: "Six."
Charlie: "Six."

Kenny: "MIX."
Charlie:  "Mix.....YAY!!  I said misk!!  Awwww..."

This conversation happened, oh, I'd say maybe 8 times, with the same exact ending every, single time.  Followed by our laughing and his frowning, begging that we do it again.  He doesn't like to not "win" and this little game of phonics was beating him. 

I personally think it's kinda cute.  Despite my big-almost-2nd-grader's lack of amusement with his x-shaped ordeal...