On things that are past, it is needless to pursue past mistakes; let bygones be bygones.

accept

find fault, nitpick, rebuke, censure / feel guilty / to question (a suspect)

past

the past (period of time that has already happened)

failure, miscarriage / mistake, fault, error

fail / make a mistake

he / distal demonstrative, something far off removed from both speaker and listener: that / boyfriend

distal demonstrative, something far off removed from both speaker and listener: that, yon / particularly, male personal third person pronoun: he / by extension from he: boyfriend

he; boyfriend