A 'sexual consent' app is being designed which claims to be a binding agreement which would stand up in court.
But lawyers are sceptical, with one calling it "offensive" and its validity meaningless.
Legal Fling is an app which allows partners to note down their dos and don'ts before having sex.
A person can choose 'yes' or 'no' for different categories, including photo and video, use condom, STD-free, explicit language and BDSM.
A request is then sent to the phone of their chosen partner through WhatsApp, Facebook Messenger or text, who can agree or disagree to the terms.
"During a fun night you meet your fling," the Dutch company LegalThings says on its website.
"Now it's time to get consent. Does your fling really want to take it further? Simply open the LegalFling app, scroll to your contacts and send a request.
"Your sexual preferences, including your dos and don'ts are automatically communicated.
"Are you into BDSM but your fling isn't? LegalFling matches sexual preferences automatically, so you're immediately aware what your fling doesn't appreciate and will not consent to."
The app uses blockchain technology, a form of public record also used for bitcoin, which cannot be digitally changed after submitting.
Obviously everyone has the right to change their mind, and no always means no - but it is unclear how this fits in to the premise of the app.
The app's website also claims it can be used as a safeguard if you need "further down the road".
"Just in case, feel safe knowing that there is a legally binding agreement," the website says.
"Any violation can be dealt with quickly and privately.
"Don't ruin the moment. Asking to sign a contract to have sex can be awkward. Get sexual consent with a single tap."
Shine Lawyers solicitor Peter Coggins told news.com.au the app is "possibly one of the most offensive things [he has] come across".
"Consent can be withdrawn at any time, which would render any prior consent given, however documented, meaningless.
"This is a very bad attempt to regulate potential criminal matters with mechanisms of civil law."
The app isn't available in New Zealand yet, however the way it is designed allows any Kiwi developer to pick it up and build their own version.