Imagine your OTP as high school students. Person A is a loner, disliked by the general population of the school. But they’re fine with this. They don’t really want anyone with them, because they’re scared of being hurt by them.
Then person B joins the school. B is a little naïve, maybe a bit childish, and when they see A all alone they feel sorry for them. Because of this, they keep approaching A to try and gain their friendship, despite that A keeps pushing B away.
How things go from there is up to you.