Mamma Mia, here he goes again!

Hizzoner began the show flying in as “Spidermike.” But because of a technical “snafu” — like those plaguing the real musical “Spider-man: Turn Off the Dark” — he had to switch to a different production.

A bell-bottomed Mayor Bloomberg later got groovy last night as he donned a ’70s-style disco outfit and joined with the cast of Broadway’s ABBA-inspired hit musical “Mamma Mia” for the Inner Circle charity dinner.

Bloomberg then performed “Mayor Mia!” with James Earl Jones providing the narration and his press secretary Stu Loeser and Deputy Mayor Stephen Goldsmith appearing as themselves.