Lelouch loves Suzaku. He's known that since he was a little boy. He's also always known that the other loves him back. It's something that's simply obvious – the background noise in the soundtrack of their lives. They have a relationship, they do. Somewhere between school and big important battles, they manage to have a relationship. A real relationship, with kisses and cuddles and sex. With heated arguments over wristwatches and teacups, with whispered sweet nothings, with shared breakfasts and "I love you"s. They go on dates once a month or so, and they eat chocolate and take strolls and go to the movies just like they're supposed to. They miss one another, they have bursts of jealousy, and they kiss in the rain. They're a lovely couple. Sorrow is for the weak and the poor.
In reality, it's a very complicated relationship that's got nothing at all to do with chocolate and cuddling. There's confusion and raw desire and a fair bit of hate.
But they can't deal with that.
So they pretend. They pretend that Zero's just a fairytale and that there's no such thing as a war and that Lelouch never killed Euphemia and that Suzaku was never in love with her. They pretend that Japan is Japan and not Area 11. They pretend that Lelouch's father isn't the source of all evil. They pretend that Suzaku never wanted anything remotely like killing his best friend. They pretend that Lelouch has no unnatural powers. They pretend that tomorrow they'll still care.
At some point they'll have to stop pretending.
At that point, the kisses will be cold and the rain will be acid.
But they go on pretending.