Well it wasn't easy , try to come out and make it very clear you didn't mean it that way and try to bring up something they like very much to cheer them up or something that you can do to repay them for wat I've said :) and it went great
Everyone does. All the time. Borrow (or buy) this book from your library and LIVE BY IT: "How to Win Friends and Influence People" by Dale Carnegie. It has been in print for many years because it has helped MILLIONS of folk manage their mouth. Just remember: you are not responsible for how anyone reacts to you or your comments. It is their interpretation that has upset them and even apologizing may make them feel worse. The best thing to do in most situations is NOTHING. That leaves the ball in the other guy's court for them to respond.