Oh yeah, of course. Was the sister better than your ex?I hate to have to admit this on this esteemed site but I too was once a victim of domestic violence in similar circumstances.
My ex once attacked me in my sleep for sleeping with her sister.
That reality was that she had dreamt that I had slept with her sister, woke up, saw me asleep and laid into me. Punches, slaps, hair pulling. Oh, and she screamed a lot, at daft o'clock in the morning.
She did that once, and she soon got her marching orders.