In 1984, how is the role of sex in Oceania similar to, and different from, its role in our own time?

If we examine sex as a political act, something that flies
in the face of cultural or political expectations, it is from this point where much of
the discussion can develop.  In social or political orders where sex is seen as
something forbidden, something taboo, or something that is frowned upon, one can see
parallels between these settings and Winston's contention that Julia was a rebel "from
the waist down."  Sex is an act of rebellion in Orwell's work because it is something
that is forbidden, a private act that has been appropriated by the public.  It is in
this light where it is seen as an act of subversion.  Hence, in different settings that
are inward in their socially gravitational pull, there can be much in way of similarity
between how sex is viewed in Orwell's novel and in these realms.  When examining the
cosmopolitan and widely accepted belief that sex is a private act, the similarities
become a bit more murky.  On one hand, when sex is relegated to the realm of the
private, there is little ground for rebellion.  When the public realm disavows the
desire or need to control this realm, the activist theme disappears.  There can be an
argument made that sex has become so publicized that there is a desensitivity to it.  In
this light, perhaps the notion of viewing sex and something other than what it actually
is might be another similarity between Winston's perception and the modern
setting.

I would say that the more interesting element here
might not be the sexual activity and paralelling it to the modern predicament, but
actually examining the theme of renunciation.  Winston and Julian both renounce one
another when confronted by the interrogation room.  Two people who shared the most
intimate of moments, the most tender of instants, end up renouncing the other and
betraying one another.  While we are repulsed by it, we understand it, to a certain
extent, because the use of terror was quite precise.  Yet, when we see the same behavior
in the modern setting, where the external use of terror is absent, I think that it
becomes quite scary because we, in a way, have become our own Big Brothers, our own
tormentors.  Perhaps, this was another one of Orwell's points being made.  In our own
behavior towards one another, Big Brother is not something separate from us, but rather
walks amongst and within us.