As someone who has struggled with SSA its not okay for them to stay in the relationship. Too many temptations to go back to the old life style is there in my opinion. Its also not a good representation of Christ. If I was a liar and spent my whole past 20 years lying and God changed me why would I continue to live as if I was still a liar? It doesn’t glorify God or show the changes that he made inside me.
In most cases with others who think this is okay they are honestly choosing to stay ignorant of what God says or choosing to ignore what God says about actively living a life that participates in homosexual acts. Just as an individual it makes me question if their trust is in themselves or God. I trust that Gods love is more important and more fulfilling that any person on this planet which is why I choose him over any romantic relationship.
As far as Salvation goes I do believe you can still be saved and confused or just not mature enough to come to the knowledge of certain things. Because of that you do have to give people time to change and sometimes let God work and let him continually convict the person(s). Before anything we do have to pray and seek wisdom from the Holy Spirit because doing anything out of our own flesh on either side of this can be dangerous.