The Butterflys were a NY based group of the Red Bird label.
The lead singer was either Mary Thomas of the Crystals or Ellie Greenwich, a singer and song-writer who also sang with "The Jelly Beans". Both girls reputedly sang on the record. The song had been written by Ellie!
The Butterflys were not a "Real" group. The label sometimes used its house artists to produce records that were marketed as being by different acts.