And this one is sort of the punchline for these incest poems

CATULLUS 91

I really was an idiot to trust

someone I know to be obsessed with sin

around my love. I thought, she's not his kin

and so she's not a target for his lust.

I'm mad for love of her, that's my excuse.

So mad I somehow thought that she'd be safe

forgot he's one whom all restrictions chafe

thought he was bound by friendship who's so loose

Normal considerations don't apply.

I burn for her with such intense desire

my common sense consumed in raging fire

He reassured me, did not even lie.

'I love her like a sister'. Should have known

that meant she's on his list of girls to bone.