Fritz doesn't say a word, doesn't boast or even hint at it, but he doesn't have to. His eyes, lit up and happy, betray him.
Ernst can't bear it. He tries not to think of Fritz and Roberta alone together in the dark: soft words and lingering kisses, passions building until they can no longer be contained, bodies straining and needy. He tries to pretend to himself it's because it's forbidden and wrong, but the thought alone cuts him to the bone, because surely Fritz choosing Roberta is the lesser of two evils.
He doesn't blame Fritz, not really. Roberta is beautiful and sweet and good, and it's so easy to forget what she really is under all those pretty, tattered dresses of hers. She seems precious, somehow, out of his league and above his station.
Ernst knows it's a sin; that underneath the happy veneer of their lives here, there is a dark beating heart that would only bring judgement and condemnation in the outside world. He knows that it's only here in their deserted paradise that they get to make their own rules and only here that Fritz would dare to have such a relationship, outside the bonds of marriage, outside the laws of God and man.
Ernst knows that the worst of it, the very worst thing of all, is that really, he's glad of their isolation. He's glad of the unfettered potential, of freedom and the joy they can find in it.
He just can't stand the thought that he is forever destined to be the one on the outside: a brother, a friend, but never an intimate, never a beloved, never a husband or a lover. It's worse still knowing what he could have had but was too afraid to take, back when it was still just the two of them. A fishing trip when the weather turned stormy and they'd had to fight against nature with all their strength to make it back to shore. Drenched and shaken, purpled with bruises and trembling with could-have-beens, they lay on the beach and let the rain fall on their upturned faces, shoulder to shoulder, waiting for their strength to return. Fritz had touched him then, just once, with such longing and unspoken question written on his face, but Ernst had frozen in a terror of indecision and Fritz had quickly withdrawn, the moment passed, never to be spoken of by either of them.
Ernst missed his chance and the thought claws at him in his weaker moments.
He knows he should be happy for them, knows that this is how things were meant to be, but he's filled with black envy and bitter loneliness, even in the bosom of their unconventional little family.
He's so confused and conflicted he can't be sure if it's his head or his heart that will crack open first and bleed him dry.
He makes a decision. He can take himself out of the equation; remove himself from the silent jealousy and the guilty lust churning in his gut and heating his bones from the inside. He'll do it tonight, by the light of the full moon, leave while Fritz and Roberta are sleeping. He'll lose himself in the forest or perhaps in the caves dotted along the beach on the far side of the island, half a day's walk away.
A fishing hook slicing through the pad of his thumb is his undoing, making him yelp and swear, loudly enough that Fritz soon appears in the doorway of Ernst's bedroom, his arrival heralded by the vibration of hurried footfalls through their little treetop house.
"What are you doing?"
Ernst spares him the scantest of glances. He sucks at his thumb; bitterness welling up inside him. "What does it look like?"
"It looks like you're packing." Fritz frowns, but it's a poor mask for that infuriating smirk of his, and he folds his arms over his bare chest. "But I have to wonder where on earth you think you're going. We do live on an island, after all."
"A big enough island that I can lose myself on it."
This, it seems, is enough to rob Fritz of his good humour. He draws closer and takes Ernst's hand to examine the wound. It's still bleeding freely. Ernst draws in a shaky breath when Fritz leans closer and lowers his head to suck at the wound himself, his lips and tongue soft against the rough calluses of Ernst's skin.
Fritz glances up, his eyes startlingly blue against the tan of his skin. "What's troubling you, brother?"
"You love her," Ernst says, the words falling out of him. "You love her and I can't bear it."
There is a flash of hurt on Fritz's face, quickly overtaken by fury. He grabs fistfuls of Ernst's shirt and spins him, slamming him against the wall, shaking the entire room. "You selfish bastard," he hisses. "You would deny me happiness?"
"N-no." Ernst shakes his head, his too-long hair falling into his eyes. "Never that."
Fritz searches his face, his anger fading into something much fonder as realisation dawns. "Oh, Ernst. You idiot." The fists on Ernst's shirt loosen, violence no longer in their hold, only strength. "I gave her all my love, it's true, but only what was left after loving you."
It takes Ernst a moment to answer, his voice cracked and wavering when he finally speaks. "You can't possibly know what kind of love I'm speaking of."
Fritz draws him in closer and presses a soft kiss to Ernst's slack lips. "There is love enough for two, Ernst, if you can accept it. It's always been there."
"And Roberta?" Ernst asks, disbelieving, his voice little more than a broken whisper.
Fritz steps away and suddenly the only thing holding Ernst up is the wall at his back. He's trembling, his knees weak, and he feels as though he might slump to the floor at Fritz's feet.
"She's readying herself for bed. Why don't you come with me and ask her yourself?"
A wave of heat and longing rushes through him, and Ernst shakes his head fiercely, terrified at the very thought. "I cannot. It wouldn't be proper."
Fritz lets out a breath of laughter. "I'm afraid nothing about our lives is proper. I can't say that I care. I prefer the choices we make to govern ourselves and to hell with what's proper." He holds out his hand. "Ernst, come with me. Please?"
Ernst glances at his meagre belongings strewn on the bed. He thinks about treks through the forest in the dead of night, and he thinks about the delicate pink of Roberta's cheeks and the soft curve of her shoulder, the way her laughter never fails to lighten his mood.
He swallows, and takes his brother's hand.