If someone really thinks having sex in a public place is a good idea, I shudder to the think what else they may, as a parent, think is also a good idea. Of course, the public sex problem resolved either by the majority of people understanding the reaction to their public sexual activity, and the arrest of those who can't figure this out, it doesn't seem to be that great an issue.
As far as others, I can agree kids would do best with male and female perspectives in their rearing, but this does not necessarily have to all come from their parents. You know, it used to be common that kids would spend plenty of time around aunts and uncles, along with cousins, as well as trusted members of the community they live in. I don't get this insistence over the last few decades that only the parents are supposed to be some kind of influence on their children. The most important thing relating to their parents is that the parents actually bother to care for them, physically, mentally, and emotionally . . . not that one have a penis, and the other have a vagina. If that's your only requirement . . . I'm sorry to tell you, but there's quite a few highly abusive heterosexual couples throughout history.