In ancient Roman religion, Mutunus Tutunus or Mutinus Titinus was a phallic marriage deity, in some respects equated with Priapus. His shrine was located on the Velian Hill, supposedly since the founding of Rome, until the 1st century BC.
During preliminary marriage rites, Roman brides are supposed to have straddled the phallus of Mutunus to prepare themselves for intercourse, according to Church Fathers who interpreted this act as an obscene loss of virginity. The Christian apologist Arnobius says that Roman matrons were taken for a ride (inequitare) on Tutunus's "awful phallus" with its "immense shameful parts", but other sources specify that it is brides who learned through the ritual not to be embarrassed by sex: "Tutinus, upon whose shameful lap sit brides, so that the god seems to sample their shame before the fact." The 2nd-century grammarian Festus is the only classical Latin source to take note of the god, and the characterization of the rite by Christian sources is likely to be hostile or biased.