<human>: Throwaway because I know my boyfriend surfs Reddit a lot.

So first off, my SO and I have been dating for almost two years now, and we're now living with each other. We met through mutual friends and so as a result, we know most of each other's friends. Our relationship has been pretty smooth overall and we've never had any major spats, but so far, this specific issue has become a recurring one and my SO has been sounding somewhat accusatory sometimes and it has started to strike at my nerves a bit.

I'll start with the context. For the last eight years, I've been friends with this guy named "Sam", and throughout the time I've known him, he's never been very social at all as he's told me he only has a few other friends besides me, and he hates going out. My SO knows about the context behind Sam and I.

And so, about about a couple months ago, my SO made a comment about having never gotten to really meet Sam, even though I hang out with him pretty often. He suggested that I invite Sam over to our home for dinner or something. I sent the offer to Sam and Sam said thanks, but declined. My SO suggested that I try to invite him over again sometime later. I did, insistent this time, and Sam came over and we had a painfully awkward dinner as neither one of them really talked to each other. After Sam went home, my SO started saying how Sam "weirded him out" and how he wondered how we could even be friends.

From then on, my SO has continuously made comments on my friendship with Sam, especially when I go to hang out with Sam, eventually saying that he felt Sam was so rude for not even trying to get to know him and other things like "why do you even hang out with him?" sort of comments. I've asked SO to stop, but sometimes he gets mad that I'm defending Sam "over him", and that my SO is just "speaking his mind". It's been getting on my nerves! How do I deal with this? I don't even get where he's getting these ideas from. Could I possibly be in the wrong of this situation?

Could you distill the essence of the text into 1-3 sentences?
<bot>: My SO keeps negatively commenting on the friendship between my male friend and I. I've asked him to stop, but he has gotten defensive at times and doesn't see anything wrong with it. What do I do?