Jonjo Shelvey blasted Newcastle’s behaviour after Eddie Howe’s side beat Nottingham Forest with a last-minute Alexander Isak penalty.
The Forest midfielder played for the Tyneside club for five years, before joining his new team in this year's January transfer window.
But his newfound allegiance was clear in his critique of his former team-mates' decorum on the pitch during Friday night's 2-1 defeat at the City Ground.
Newcastle appealed heavily for two penalties during the match, the first in the opening 45 minutes when Bruno Guimaraes was challenged in the area, but was only awarded their second.