Each of the guys in the band had been romantically involved with the Giant Woman
It would explain the "used up all of my friends" line. The guys in the band are all close (with lead singer A.Jay and guitarist Jeremy actually being brothers), making them the "friends" the lead singer is referring to. All of them being her former (or concurrent) lovers could explain why they would be so comfortable walking all over her body while she relaxes in a bikini. Something that strangers probably couldn't get away with, even given her actual reasons for allowing this. It would also fit into the fact that she's supposed to be a maneater. The Giant Woman from the music video was later destroyed by the US Military...
...But a doomsday cult that worships her builds a robot and uses it as a vessel for her soul to operate, which she used to eat Queen (and, just For the Evulz, several innocent bystanders), as famously depicted on the album cover of their album "News of the World". Now, you may be asking yourself, "why does she take so much pride in eating rock bands?" The answer to that is simple: She has a fetish for that sort of thing. And to fulfill her fantasies, she will eat every band on Earth, and your favorite band is next...- Or rather that robot was supposed to defend against people like her, but when it went rogue it was destroyed. Leaving future bands vulnerable.
The Giant Woman is the lead singer's girlfriend.
Considering the fact that he is singing the song to her it's not a stretch to assume that he meant it to be about his relationship with her. It would explain why she is letting him walk all over her body, including some rather personal areas, with impunity. She also gives him a notable smile when she's dangling him in front of her face, about to eat him, implying she has/had some fondness for him. Going further, the other band members (the which consist of the lead singer's IRL brother and friends he's had since high school) are the "friends" of his she's apparently "used up" which is why she's letting them walk on her too and why she eats them first.