be unfaithful

abandon deceive forsake mislead seduce

bluff cross delude desert finger jilt knife trick

bite the hand that feeds you blow the whistle break faith break promise break trust break with commit treason deliver up double-cross go back on inform against inform on let down play Judas play false sell down the river sell out stab in the back take in turn in turn informer turn state's evidence walk out on

aid assist help stay

be faithful be loyal be quiet defend hide keep secret protect support

renege

abandon betray change desert forsake repudiate retract return revert

abandon betray desert forsake leave in the lurch renege repudiate retract return revert run out on

keep promise

abandon backstab be disloyal betray break promise commit treason cross deceive double-cross finger go back on inform on play Judas sell down the river sell out trick turn in turn informer turn traitor

betray burn cheat con deceive defraud dupe mislead trick victimize

backstab be dishonest be disloyal double-cross take advantage of

aid be honest help protect support