Most abusive people don't behave abusively all the time or even most of the time. Real abuse is sporadic, intermittent, occasional, temporary and sustained only for short bursts. It doesn't take much mistreatment to terrorize or demoralize a person for a very long time. It is quite common for an abusive person to behave normally most of the time and even be kind, polite, humble, gracious, generous, devoted or apologetic in periods between and immediately following episodes of mistreatment. This is often how an abusive person draws a victim closer to themselves between outbursts. It is also common during these periods for an abusive person to want to "rewrite" their own history or try to influence their victim to misrepresent or ignore past events, as a way of justifying themselves or dealing with discomfort about their abusive behavior. The victim will often play along, grateful for a period of calm, "letting sleeping dogs lie" and hoping not to provoke any further outbursts.
FROM OUT OF THE FOG website