Answer: takestwototango

AnswerCrossword Clue
TAKESTWOTOTANGO"I'm not the only one to blame!"
TAKESTWOTOTANGODependency adage, with "It"
TAKESTWOTOTANGO"It's not only my fault"
TAKESTWOTOTANGOSong popularized by Pearl Bailey
TAKESTWOTOTANGORequires more than one person, in a saying