A WOMAN accused of unlawfully performing oral sex on her ex-husband has no case to answer, the Adelaide Magistrates Court has heard.

The woman, 49, is charged with engaging in sexual intercourse without consent in August 2011 at an address on the Eyre Peninsula.

The complainant said he was awoken by his ex-wife performing fellatio on him.

She appeared in the court on Friday when her lawyer said she had no case to answer, noting it involved the woman’s word against the complainant's.

The case was adjourned until September 6.