Even if you confess your sins?
This is what I don’t understand is that in the churches (Catholic and Eastern Orthodox) that they will marry a couple, they get divorced and then each remarrying whom they had the affair with and remarried in the church, too!
One of my relatives in on her 4th marriage.
Each time it gets easier.
If you divorce your spouse from a valid marriage and then marry again without having the first marriage annulled then you are engaging in an adulterous relationship. You can't just confess your sins from that knowing that you are going to continue sinning. People living such a life are expected to avoid taking the sacraments, and could be denied them by their priest if they don't forego them voluntarily.