Relationships should not feel forced.
I'm talking about relationships with anyone in general. Your friends, your significant other, family, etc. Close relationships like that should be easy to deal with. It should come easily. You should be able to be yourself, speak your mind, and never get bombarded for the type of person you are (unless the type of person you are is a bad one).
If at some point you ever feel like your relationship with that person seems so "forced", perhaps...that person doesn't mean much to you as you're letting on.
Do yourself a favor and save the other person the hurt of being friends with someone who apparently can give two shits about, and just tell them straight up.
It's time for new friends.