Indeed it's exciting.That's a very limited view. Given the last hundred years of technological advancement in every possible field of science and engineering it's difficult to believe that anything is impossible. I don't think artificial sentience is as much a matter of "if" as it is "when." We've only really had computers for 60ish years, and widespread computer use far less than that, and look how far it's come. Our knowledge and technology is advancing at an accelerating rate, there's no telling where it'll go. This is a very exciting time to be alive.
And like you said, you can never be sure. What I meant though was that these ideas of robot-friends or lovers seem a bit too extreme.
Maybe in millenias to come, that far off into the future is impossible to imagine. But not during my life-time.
Also, having sex with a robot will most likely never be a mainstream thing. Once technology allows it, some people will probably do it. But I find it hard to believe it will be socially acceptable.