
Yes. People can be a victim of something and still perpetrate that (or something else) to others. Actually most times perpetrators were victims themselves (ie abusers were abused themselves as children, victims of molestation and child rape end up consuming csam as adults, many criminals are abuse victims, etc)
No, you can be the victim to one thing as well as the perpetrator to another. Life isn’t always black and white and it’s bad to think so. This could be a grey area which ofc not always very possible. Emotional distress can cause people to act irrational and do things they may not have done under other circumstances. It definitely depends on the details of situation and you’d have to take into account both perspectives, this is why court and jury is a thing.
Look at the Gypsy rose case, Gypsy was the victim to medical abuse and manipulation from her mother, she then in turn klled her mother the abuser. Her being the kller makes her both a victim and perpetrator in the situation. Now ofc OP is probably talking about romantic relationships and it’s probably way less intense but it’s possible for a victim to be a perpetrator even in thoes situations.