The man, who cannot be identified for legal reasons, pleaded guilty to four charges of having sex with a child aged 14-16 years in Wollongong Local Court on Wednesday but will remain on bail ahead of his sentencing date in April.

The girl told police the assaults took place over a six week period in July/August last year and included at least one incident where the teen said she was “pinned” to a plastic chair so her cousin could take advantage of her.

The man was arrested in mid-August after a complaint was made to police.

In a subsequent interview, he admitted exchanging nude photos with his cousin for almost a year before travelling to the Illawarra to stay with her family, at which time their relationship turned physical.

He also admitted penetrating the teen and having her masturbate him, but told police his cousin had instigated some of the sexual touching.

He claimed during one incident his hand “fell onto her vagina” when she put his hand on her thigh, while on another occasion his fingers “slipped into her vagina” after she’d placed his hand down her pants and began moving her hips.

A series of text messages between the pair, obtained by police, shows while the acts were consensual, the girl repeatedly expressed her unease at their relationship and concerns her mother would catch them.

“We aren’t doing it anymore, ever again,” she wrote after one sexual encounter between them, prompting an “aww damn it” from her cousin in response.

He attempted to reassure her they would not be caught before telling her “but you are amazing, it feels so good”.

She replied “I’m your cousin dude, I shouldn’t be doing that shit”.

The man left the house after an argument with his aunt – the girl’s mother – over an unrelated matter, leading the teen to disclose the indecent acts to her mother.