California is the first state to officially outlaw "stealthing" - the practice of removing a condom during sex without your partner's consent.
Gov. Gavin Newsom signed the bill into law on Thursday, declaring the practice 'sexual battery' and subject to legal action and punitive damages.
'Stealthing' can unknowingly expose victims to STDs or unwanted pregnancies.
The bill's author, Assemblywoman Cristina Garcia, called on other states to join California and "make it clear that stealthing is not just immoral but illegal".