I wish I could say that God doesn't grieve about my responses to Him when He tells me what is best for me and I move on to do as I please. How does God respond to us when we really don't want His opinion? He loves us. He cares for us. Is there always condemnation? No, right. If there is sin, point it out with all doctrine (Scriptures) and longsuffering but remember Matthew 7:6? If he responds like a dog, i.e. get's angry, or like a pig and tramples every word you have to say underfoot without the barest consideration, stop sharing your pearls and what is holy with him. Just like then love him and pray for both him and his girlfriend. When we do the same with God's words, how does He respond to us? Reproof? Maybe, if we practice sin and do not repent.
"1Co 11:28 But a man must examine himself, and in so doing he is to eat of the bread and drink of the cup. 29 For he who eats and drinks, eats and drinks judgment to himself if he does not judge the body rightly. 30 For this reason many among you are weak and sick, and a number sleep. 31 But if we judged ourselves rightly, we would not be judged. 32 But when we are judged, we are disciplined by the Lord so that we will not be condemned along with the world."
If you are wondering what the sleep part refers to, check out 1Co 5. And if he, or the rest of us people who believe we are Christians do not see this reproof from God, check out this passage: Heb. 12:3-14
But that reproof is God's to perform. Pray, reprove once (With all doctrine and patience) and look for the response. Sometimes the reason others shut us down or get angry is because we kept sharing when God commands us to stop ... then we wonder why things go wrong... and sometimes get angry at God for the consequences of our own disobedience.
Have you noticed that we are far more interested in fixing the sins in the lives of the others we care about and getting them obedient to all of God's commandments than we are in figuring out and doing exactly as God commands for ourselves?
I cannot have a relationship with God/truth for anyone else, nor can they have that relationship for me, any more than they can have a relationship with my wife and kids "for" me. This is time for you to figure out areas where you fall short and repent. If you have sinned, confess it to those who were present. It could be that you owe your son, and his girlfriend an apology because you disobeyed God.