I don't agree it's a "MUST". We all know that at this moment right now, gays are serving in the military without any major problems. They eat, work, and sleep along side straight soldiers and other gay soldiers. Many times, the other soldiers already know their sexual orientation. I give our soldiers enough credit to act respectfully and professionally towards each other regardless of sexual orientation. I don't think that's too much to ask.
By the way, does anyone know how it is handled in other countries that allow gays to openly serve (ie. Britain, France, Germany, Canada, Israel, Russia, Spain, etc)? I'm having a hard time finding this out.