Is he being too judgmental?

My brother is in his first relationship since he came out. It’s honestly his first relationship ever (that I know of) and he was fairly desperate to find someone. I don’t blame him, he’s nearly 28 years old and is wanting physical intimacy and companionship. He deserves it. He’s a great person and I’m so happy he’s finding his happiness. However, I think he’s unsure what’s a good relationship and a bad one. I know it’s a learning experience and I told him that it’s his first relationship and he will learn as he goes.However, in general, he’s a very picky person. With everything.. clothes, cars, jobs, people, etc. He likes what he likes and there’s nothing wrong with that. But, I think he’s a little too picky when it comes to certain things. If someone does just one thing he doesn’t like he thinks they’re the worst. Like if a friend likes something he doesn’t like he automatically writes them off as his friend. I personally think he’s being harsh and overly judgmental, but it’s his choice and that’s that.But now that he’s in this new relationship, he’s overly criticizing him. That’s just my opinion. He thinks this guy doesn’t do his hair nice enough, he wears out of style clothes, he doesn’t eat as healthy, he doesn’t work out as much, he’s a little pudgy, he likes horses.. I mean, everything. And he asks me for advice and I’m like IDK! If he feels it isn’t right, then it probably isn’t. But I don’t know what to tell him for advice. I mean, I feel I’m a fairly easy going person and accept flaws easily. But I don’t want to tell my brother that he should continue on with this guy if he feels it isn’t working. He says he’s physically attracted to him and they get along great, but there’s these little things he gets caught up on.What do you think I should tell him? He leans on me for support because he doesn’t have many friends. And I want to help him the best I can, but I don’t want to say the wrong things.Help!TL:DR; Overly judgmental brother is in his first gay relationship. He’s getting caught up on little things and wants my advice on if he should end it.