babyface turn
n.— «Merlin (Stephen Dillane) seems to be warring with Arthur’s crazy-brave knights, until he pulls a babyface turn (as they call it in wrestling) and decides to join the fight for Britain against the Saxons.» —“Review: King Arthur (2004)” by Ryan Ellis Usenet: rec.arts.movies.reviews July 14, 2004. (source: Double-Tongued Dictionary)