First and foremost I am an anxious person, so bear that in mind here
Secondly, I do not want to shout about it for the sake of it. I would rather have an idea of how I will tackle the inevitable than go in blind at the time. Without a partner you are correct, I will not be forced into a position where I need to say something.
Since of course we can’t do anything but urge you to avoid embarking on a genital relationship outside of a marriage (that is, a valid heterosexual marriage), I’m going to assume you are asking how to handle friendships that could come to include a living arrangement that your grandparents and others in your family may never cease to find disordered or morally repugnant.
I agree with your wise stance that you do not go looking for social conflicts. I imagine that you are that way generally, and this instance is no different. Kudos to you; that is a gracious and civilized way to live.
What you can do is to continue to graciously avoid giving your unsolicited opinion about the life choices of others yourself. Having gained and kept that standing honestly, thank others to refrain from giving unsolicited opinions about yours. I don’t mean just about your sex life. I mean about your life generally. The less you invite others to comment on your life choices generally, the more you will have the reputation to impose the same boundaries in this case.
What you cannot do is to countenance anyone treating anyone else as a human being of less dignity than themselves. This goes twice over for those who deserve your protection because they have entrusted you with their close friendship. These and those who have no friends ought to have the greatest claim on your unwavering protection of their dignity. There is no way you ought to accept a Christian who claims the right to do anything else. For this is what Our Lord taught Christians to do with brothers in the faith who did not observe our moral laws: “
If your brother sins, go and tell him his fault between you and him alone. If he listens to you, you have won over your brother. If he does not listen, take one or two others along with you, so that ‘every fact may be established on the testimony of two or three witnesses.’ If he refuses to listen to them, tell the church. If he refuses to listen even to the church, then treat him as you would a Gentile or a tax collector.” (Matt. 18:15-17) Our Lord treated Gentiles and tax collectors as children of God who, although outside of the community of Israel or of the Church, were still worthy of the love of God and the simple human kindnesses of recognition of their presence, conversation, and the like. He avoided conflict, he held gatherings in which he invited the few instead of the many, but on the whole he shunned no one.
Therefore, the way I would handle this is to say, “Grandma and Grandpa, I can appreciate that my choice in this matter violates your morals*. What I cannot allow is for you to treat my friends in a way that is less gracious than you treat anyone else’s friends. John and I are a social unit–that is mine to choose. I expect that where others are invited as a social unit, he and I will also be invited as a social unit. Where others can expect to show affection as they please, within certain boundaries of propriety, we will expect to be able to show affection as within the same boundaries–no greater, but also no less. I can’t demand your approval. I can insist on your acceptance of us as two people who deserve to be treated with the same welcome you give everyone else, even though we are all undoubtedly living our lives in ways that we haven’t vetted with you. Can you do that?”
Notice that this is pretty much exactly the same advice I would give if you were in a heterosexual relationship or even a business relationship that your grandparents thought was morally off the tracks. The way you protect all–your friend’s dignity, your dignity, and your grandparent’s closely-held beliefs–is to consider how this is handled when people have other deeply-held differences. If your grandparents do not socially shun anyone who has a serious moral difference with them, they will probably be able to accept it if you present your situation like that. If, OTOH, they do not invite the second wife of your cousin to their gatherings because they believe your cousin is committing adultery by divorcing his first wife and re-marrying outside the Church, don’t be surprised if you are subject to the same rule.
Of course, the greatest rule when it comes to the treatment of our friends is to communicate with our friends about how they themselves handle these things and feel about these things. That, you cannot know until you have someone to ask. Should the time come, do make it a point to talk about it. This, again, falls under the heading of the Golden Rule.
*
Note that I did not say “my way of life violates your morals.” This is one choice on which you differ with them, not your whole life. You probably still share much of the territory of your moral opinions with them. Don’t assume that all has to be thrown out; you’ll want all the common ground you can get.
