Well, for one, I wouldn't subject any young children of mine to serious displays of romantic affection in movies (ie., really sucking face and going at it) if they saw two men kiss affectionately I would explain to them that there are different kinds of love between people, and that sometimes men love other men, and women love other women.
And should they see two people of the same gender really going at it in public, I would again explain the different kinds of love, and then let them know that some people have no sense of decency, no matter what your sexual preference. Basically, the same way I would explain two heterosexual people really going at it in a public place. Public Displays of Affection are unneccisary when that extreme.
However, I don't plan on having any childbeasts of my own, so this won't be an issue.