Choose someone who is a good forgiver
Relationships take a lot of hard work and you will both inevitably mess up, hurt each other, make mistakes, and otherwise generally behave like jerks to each other from time to time.
So choose a life partner who can accept your apologies after you mess up, who can move past arguments with you, who can forgive you for not being your kindest self sometimes. Messing up in a relationship is inevitable. It’s the repair, the willingness to forgive and come back together again, that counts.