First off, I'm absolutely sure there was an intention to portray a slashy relationship in this scene. In 'Doctor Who Confidential' John Simm made a point of saying 'What I did with that role is what was in the script.' In other words, he is saying: this is what I was told to do, and I did it. I posted a link to that audio clip and images because I think if you give your full attention to either the sound or the visuals it is even more obvious than if you are trying to assimilate both at once. Listen to the way Simm says 'Doctor' (after a 10 second pause - which is a long time) at the start of that conversation. And look at the poster behind David Tennant's head all through that scene.
Now, for me, these are two very attractive men, so that gives it a bit of extra frisson compared to a heterosexual sex scene, such as the straight bonkbuster 'Talk to me' on ITV on Sunday evening, which is you know, pretty good, all about love and sex, Max Beesley agonising over his best friend's wife, and you get what it says on the tin. But I think there is something else which makes this scene so exciting, which is not about my Pavlovian '2 legs good, four legs better' response. Actually... mmm... four legs. No, pull yourself together, woman.
kerravonsen says she liked the scene and she didn't see it as slashy at all. And I think that's a fair point, because what makes it a good scene is not this one flavour, though if you like the flavour you tend to concentrate on it. For some people the scene is about non-erotic love (for instance).
I was talking a while ago about Hegel and the Master/Slave dialectic. I'm not saying RTD was influenced by Hegel. I'm saying that both Hegel and this scene reflect some basic interesting drives within human beings. Each person seeks to be validated by interaction with some other entity, and we simultaneously want this entity to be free and powerful (so that it can authenticate us) and yet under our control (so that it does not destroy us). Taking a totally non-sexual example, the explorer wants the new continent to be hard to traverse, so that it makes him feel real, but he doesn't want it to be so impassable that he dies in the attempt.
In any Master/Slave relationship, the Master never feels quite real, because if he controls the slave, then their praise and love become worthless. The Slave, paradoxically, has more chance of authenticity because he is struggling against control, which gives him validation. In this way The Master finds that gaining control over the human race is an exciting challenge, but once he has done it, it turns to ashes, and he needs to Doctor to come and admire his achievement, as a free entity.
So, that's the underlying Need which is dramatised in that scene - that we need each other to be free and equal in order to feel real ourselves.
Of course in real life nobody is entirely the master or the slave, they are fictional entities, and to be consumed entirely by one role, as The Master is, is to be insane. But this type of scene is exciting because it dramatises the dynamic of asserting our human identity. The paradox is a validating challenge because it is impossible that it will ever be resolved.
BTW if I was going to make a fanvid of this episode I'd use the Pilooski re-mix of 'Beggin' by Frankie Valli and the Four Seasons.
ETA Hegel puppet