Strawberry Switchblade, Love the name by the way. Remember that these people who are talking crap are making assumptions on little or no information. What they are seeing scares the crap out of them and they are concerned for the health and safety of their friend.
I don't really see how it impacts you in the long term unless you feel R is likely to be worn down by such behavior and it threatens your relationship. Their feelings, ideas, and actions are just that, theirs. Their reaction is perfectly normal to what they think they are seeing. They have a right to it just as you have a right to what you know to be true for you. Neither you nor R is responsible to change their minds.
So if you have no choice but to deal with them directly, remember it's like dealing with frightened children. Treat them with kindness and patience remembering that you have a happiness and understanding that they may never have.
They may come around, they may not. If you don't have to deal with them directly, don't worry about it. They are R's friends and they will take their cues from him. If he loses them over something like this all you can do is be there for him.
Hang in there. Often the most beautiful places have the longest most dangerous hikes in. peace.