As it was very nicely written before, I quote:
In the Czech Republic, § 188 of the Criminal Code only states: "Soulož mezi příbuznými:
Kdo vykoná soulož s příbuzným v pokolení přímém nebo se sourozencem, bude potrestán odnětím svobody až na tři léta."
This means: "Intercourse between relatives:
Anyone who has sex with a relative of a direct generation or with a sibling is punishable by up to three years' imprisonment."
But there can be a small misunderstanding because in that translation of phrase there was a word "sex" used incorrectly, at least in my opinion. Intercourse is a translation of word "soulož"
And when you look up for definition of word "soulož" you find as first point in google this definiton: "Za soulož (coitus) je třeba pokládat spojení pohlavních orgánů muže a ženy"
which means "Intercourse is considered to be connection of reproductive organs between a man and a woman"