Being happily married for 23 years and counting makes me see this question differently. I'm interpreting it as "What trait or characteristic instantly repels you from someone?" and for me, this isn't in a romantic sense but more in the desire to even want to further a conversation or wanting to get to know someone further as a friend or even as an acquaintance--because all types of interactions can potentially drain positive energy.
One of the biggest trait that repels me is the "Know-It-all". This is the personality that exudes superiority over all topics, most especially topics that are the most polarizing and controversial. And sometimes they "know it all" even with situations they clearly haven't had experience with--like parenting, psychology (they know you better than you know yourself), personal lives of celebrities they've never met, etc... Usually this person is just blatant about stating their opinions and dominating conversation. They know it all. And they will let YOU know that you don't. Or that you're wrong--often making it a point to cut down your intelligence in order to lift themselves up. It took me some time in life and adulthood to see this trait for what it is (and I've met many that fit this criteria--do I somehow attract these types??) and put it in its place on how I react it. To put it plainly, I don't. Just smile and nod.
The other trait that is highly unattractive to me (a very close runner-up) is the personality type that always has something judgemental to say about others--how they dress, what their hobbies are, what type of food they like to eat--like why do you have something hateful to say about everything? It's obviously toxic and as I get older, I'm NOT about it at all. It's a no thank you, next, for me. 😏
