According to report, a large number of couples are signing prenuptial agreements - traditionally the domain of the rich - not only to protect their assets but also their lifestyles.
Family lawyers have reported the prenuptial 'bug' has caught ordinary people too.
With one in three marriages ending in divorce, lawyers say couples are becoming more realistic about their relationship's future prospects.
Rather than focusing solely on how to divide up assets, lawyers have revealed that a large number of couples are inserting conditions into their prenups that dictate a partner must not gain an excessive amount of weight or must remain faithful.
This mirrors a similar trend overseas, where prenups are being used to stipulate an ever-broadening range of expectations in a union.
Jackie Vincent, partner at Australia's largest specialist family law practice Watts McCray, said her firm was drawing up more prenuptial agreements and BFAs than five years ago.
"The main reason I have come across is that people are either older and want to protect their own assets, or they have been through a separation before and they want to make sure they are protected," The Daily Telegraph quoted her, as saying.
In celebrity prenups, infidelity clauses are common. Michael Douglas agreed to pay Catherine Zeta-Jones millions should he stray, and Denise Richards made similar requirements of Charlie Sheen.
Others such as Paul McCartney, Greg Norman and Jessica Simpson have been stung for millions in divorce settlements without a prenup.