Lyric discussion by sumwhatfunny 

one of the fan site's has an interpretation of the song, and here's what I got out of it..................... Right after Lindsey broke up with Stevie, she had an affair with Mick Fleetwood (who was still married). They didn't tell Lindsey about it, but he still knew about it. So whenever he says "why don't you ask him..." he's wondering why Mick's wife hasn't been more suspicious, and whenever he says "why don't you tell me..." he is refering to himself and stevie. The site also said that Mick used to refer to his manhood as his tusk, which if this was a way for Lindsey to get back at stevie and mick, then that meaning of the word tusk would fit well...

songfacts.com/detail.php

well.. maybe you have a point.. but I was compelled to look up the meaning of "Tusk" when at my daughters high school homecoming game last night the marching band started playing Tusk... love the song. My friend and I were wondering the meaning ourselves.. Penis is what I found. So.. there you have it.

hmmm.. that link doesn't bring you right to the page. Here is what it says:

The "Tusk" is slang for penis, so the song is basically about sex. When Stevie Nicks heard the album was going to be called Tusk, she objected, but Mick Fleetwood really wanted to use the title, so he ignored her and she dropped the subject.

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