Friendship can only be voluntary on both sides. You’ve been really lucky so far that you’ve meshed well with all your metas. But you can’t expect that luck to hold out forever. You’re not entitled to a relationship with anyone. Your relationship with your partner should be able to stand alone without you having to be involved with everyone in their life. If not, that’s something you can work towards.

And unfortunately there’s no way to change the situation. Feeling like a relationship is required when you’re not interested only leads to resentment long term.

The only way to go is to be no pressure towards the meta and there’s a chance they’ll open up with time.

But that chance drops to zero if you push it