My brother and I are both 24, male, and twins (though we are fraternal and as physically different as possible).
We have a healthy sibling relationship with many shared interests (video games, book series, TV series etc.). When I was at his house, I went to Bing a question on his laptop and saw that he had pornographic furry websites open. He must have forgotten to close them and I didn't say anything about them.
But, as the title suggests, I am also a connoisseur of such material and could suggest/share some websites or art that we have a shared interested in.
The problem is, as close as we are, we have not discussed our sexual interests and starting might be awkward. We both live in the Unites States and this type of interest is usually frowned upon.
One possible issue that I would want considered is that he is shy and might reject that he has this interest and I definitely don't want to shame him.