Well, here's what the UUs think, anyway.

From the Sex Ed curriculum, Our Whole Lives (there's probably a better link on the US UU website, but I'm too lazy to go looking or it now).

• This curriculum is also based on the following assumptions about human sexuality:
  All persons are sexual.
• Sexuality includes much more than sexual behaviour.
• Human beings are sexual from the time they are born until they die.
• It is natural to express sexual feelings in a variety of ways.
• People engage in healthy sexual behaviour for a variety of reasons, including to express caring and love, to experience intimacy and connection with another, to share pleasure, to bring new life into the world, and to experience fun and relaxation.
• Sexuality in our society is damaged by violence, exploitation, alienation, dishonesty, abuse of power, and the treatment of persons as objects.