The other person uses insults, manipulation, or belittling language. You feel unsafe, anxious, or devalued. The conflict drains your energy rather than energizing you.
You both feel a strange pull toward each other despite the disagreement. Love at First Fight
If you found your partner through a trial by fire, congratulations! You likely have a highly passionate connection. Here is how to make sure that initial fire builds a warm hearth rather than burning the house down: The other person uses insults, manipulation, or belittling
Here is a complete, ready-to-publish blog post on the topic. Love at First Fight: Why Sparks Fly When Tempers Flare The other person uses insults