Friction in the group

I recently found out that my boyfriend and a very close mutual of ours have very strong feelings of dislike towards another of my close friends. While I'm relieved that it isn't me that's the problem, I'm unsure of how to handle it, and it's clearly causing my boyfriend irritation to be around him. While I can't choose between them, I feel unable to carry on as we were now I know that I was completely oblivious to this underlying tension. What do I do???

Ask your BF why the dislike is very intense about this person. Regardless of the reason for your BF's dislike, he owes you an explanation as to why he dislikes your friend so much...and it needs to be pretty genuine because this person is YOUR close friend. Be wary, because BFs can come and go but close friends are just that..close friends.