I was so worried at the time of this happening, I didn't explain properly. I don't allow my bucks together because neither of them are neutered. He was humping my younger rabbit, and doing his little grunts as he always does when around my other rabbit, so I picked him up immediately and he was erect (this is what I meant by out) but the coloring it was got me worried, it was pink with a blue? I was so surprised I didn't even look for as long as I should have. I've seen some pictures online of their gentiles with some blue undertone, so that's what got me to believe it was alright.
Either way I will be bringing him to the vet tomorrow. I don't know if he could have done it to himself, or my other rabbit nipped him. I've seen his testicles once, and they were pink. He has a lot of hair so it's difficult to find them. His behavior is like always, and shows no signs of pain. I'm going to check him again - should the color of his private always be a pink color? Any undertones of blue or a pale color? Thanks a lot.
As for nuetering, I trust no vet where I live, and have to come to the decision of whether or not I do get him neutered. Even my family agrees that here in Ecuador, where I live, they will only kill him in the process. So I'll have to take into consideration a lot of factors, as he is going on 6 months I believe and still has a nice personality, and does not spray.