I couldn't agree more with Ms. Spice! Being monogamous won't prevent you from getting those viruses that stay in a human body forever, like herpes or HPV. Also saliva and microorganisms that live in one's mouth can cause lots of unpleasant things for ladies with sensitive vaginas. For instance, I'm very prone to yeast infections and it was one of the reasons to stay away from oral for some period of time and try those dental dams. Not the best experience ever, I'm not interested in using them anymore even if it means no oral at all. No thanks. It's not easy to get things going with even without a thick barrier on top, so dental dams make oral worthless
However, again, there certainly are reasons to use dental dams even in monogamous long-term relationships. They are just not for everyone, I guess.