'Sex tech' is already advancing at a pace and in 50 years' time early 21st Century physical relationships might seem very primitive.
Virtual sex is developing alongside technology that has the capability to totally transform our physical experiences.
Already you can order a mannequin partner online. And robotic, interactive, motion-sensing technology is likely to become more and more central to the sex industry in the next few years. It could really start to enable mannequin partners to 'come to life'.
Many current technologies are designed to enhance sexual experience with a partner. Others are designed to help improve performance, which can often increase sexual confidence.
However, as robotic sexual technology advances, it is also likely that social norms about sex and relationships will change in the future.
We tend to think about issues such as virtual reality and robotic sex within the context of current norms. But if we think back to the social norms about sex that existed just 100 years ago, it is obvious that they have changed rapidly and radically.
Robophilia may be alien now, but could be normal in the near future as attitudes evolve with technology.
As virtual reality becomes more realistic and immersive and is able to mimic and even improve on the experience of sex with a human partner; it is conceivable that some will choose this in preference to sex with a less than perfect human being.
People may also begin to fall in love with their virtual reality partners. This is an issue explored in the recent film Her, in which Joaquin Phoenix's character falls in love with an operating system.
This may seem shocking and unusual now, but we should not automatically assume that virtual relationships have less value than real relationships.
The fact is, people already fall in love with fictional characters though there is no chance to meet and interact with them.
We should also remember that there are already many people living alone, people who perhaps have not been able to find a partner, or have lost a partner. Virtual sexual partners may provide significant psychological benefits for them - after all a virtual partner is surely better than no partner at all.
For those already in an intimate relationship, the psychological impact will depend on how they handle the co-existence of real and virtual relationships.
Most people successfully integrate other forms of virtual reality into their lives, but virtual sex - not to mention love - will be seen by some as infidelity, and this will present real challenges to some relationships.
In the world of the future, we could well see human relationships increasingly conducted entirely online.
And, as some people start to prefer technologically enhanced virtual sex to sex with humans, we may also see greater numbers of people living alone, spending more time in virtual reality.
Based on data suggesting that many young Japanese people are already avoiding sex and intimate relationships there are some suggestions that this may already be happening. Japanese men are already taking their virtual girlfriend apps away on holiday with them to the island of Atami.
Currently the lack of human contact could be harmful. Humans are naturally sociable and a lack of human interaction could lead to loneliness and isolation, which are linked to various mental and physical health problems.
But, in the long term, technology may overcome these problems.
When eventually there are intelligent robots indistinguishable from humans - apart from their lack of bad habits, imperfections and need for investment - not only are we likely to choose them over 'real' humans but psychologically we will not suffer if we are not able to tell the difference.Suggest a correction