Glad to hear you still had a good time together with your friend. As others have said, there's no need for things to STAY weird; you just need to all agree - together - to let it go. You could thank him, though, for helping to make your fantasy a reality. He'll probably blush or something and say he "didn't help much", or go as far as even apologising for the performance problems, but you can assure him that you've done some reading up on it (here at the board) and found out that its surprisingly common and a very normal reaction when just starting out. Plus it didn't take away from the fact that you still enjoyed yourself! You just didn't realize that it would affect your friendship the way it did, and that is your only regret. So. Can you all just agree to put it in the past? Write it off as an experiment gone awry? Something you'll all laugh about, perhaps, in the years to come? A private joke between the 3 of you?
And I would do just what you are worried about doing: carrying on as you always have. Another discussion you should have is a deep talk with your boyfriend, letting him know exactly how you feel about the whole situation, how you feel about him, and how you feel about your friend. Let him know what your fears are. Get this stuff out in the open, and if you are having doubts or fears or any other issues, your boyfriend is your first stop. You and he are the team, here, and in a team one hand knows what the other is doing at all times. He can't make effective decisions without being fully informed, so keep him up to speed at all times. Nothing you tell your friend should be news to your boyfriend.
Sure hope you guys can get back to business as usual. No point in throwing out the baby with the bathwater, right?
Good luck