Whew! Lots of comments on this. I’ll weigh in, a little.
Yes, it does not seem fair. What’s more, perhaps it does not seem merciful.
As a guide, the Linns of Linn Ministries say that we can fall back on “God loves us at least as much as the person who loves us most”. If the person who loves us most forgives us without our even asking, then that might be a good guide. OTOH, what is my relationship like with someone if I hurt them or trespass against them without feeling sorry about it, without asking for forgiveness when such helps with the realization of reconciliation and genuine relationship?
So, the way I look at it is that Jesus is not saying “If you don’t ask the Father for forgiveness, He won’t forgive you.”, we can look to the image of the prodigal son’s Father. What He is saying is more like (IMHO) “If you don’t ask God for forgiveness, reconciliation is incomplete. Relationship involves some action from both parties.” Again, we can use the parable of the prodigal son as a guide.
Does that make it all seem more “fair”, or more confusing?