The sex seemed normal until it was over and Rebecca discovered her boyfriend had secretly removed his condom.

New fears sprang up to torment the college freshman, according to a 2017 journal article documenting her account: What if she became pregnant? Did he have any sexually transmitted diseases? How had a trusted person violated her like this?

Later, as a graduate student working a rape crisis hotline, Rebecca — who was given a pseudonym in the journal article — heard similar stories from women whose partners had also engaged in the act of “stealthing,” or removing condoms during sex without their partners’ knowledge or consent. The victims struggled to describe their experiences, but many started with a common refrain.

“I’m not sure this is rape, but …”

New legislation in California would make stealthing illegal. State lawmakers on Tuesday sent a bill to Gov. Gavin Newsom (D) that would add such behavior to the state’s civil definition of sexual battery. If Newsom signs the bill, introduced by Democratic Assemblywoman Cristina Garcia, the new law would allow victims to sue perpetrators for damages but would not make it a crime that could result in jail time.

Such a law would make California the first state to explicitly address nonconsensual condom removal, experts told The Washington Post earlier this year.

Recent research suggests stealthing is “depressingly common,” California legislative analysts wrote in assessing Garcia’s bill. A paper published in 2019 found that 12 percent of women ages 21 to 30 reported they had been victims of stealthing. About 10 percent of men in that same age group reported that they had secretly removed a condom during sex an average of 3.62 times since they were 14.

A more recent study found as many as one-third of sexually active respondents had a partner take off a condom without their consent, according to a report by California legislative staffers.

Garcia has been trying to get similar legislation passed for four years. She introduced a bill in 2017 that would have made stealthing a crime, allowing prosecutors to go after perpetrators criminally and put them behind bars. The legislation didn’t pass.

Legislative analysts at the time said stealthing could already be considered misdemeanor sexual battery, even though it’s not explicitly mentioned in California’s criminal code, the Associated Press reported. But they acknowledged it is rarely prosecuted, noting it would be difficult to prove a condom was removed on purpose and didn’t come off accidentally.

Garcia said she tried a different approach this year to broaden support by making it a violation of the state’s civil statutes. It worked. Her most recent bill passed both chambers unanimously.

Chloe Neely, a victims’ rights attorney with the Fierberg National Law Group, told The Post earlier this year that cases involving consent are “incredibly difficult to prove from a legal perspective. It’s difficult for a jury to understand that consent is fluid and not a rigid on-off switch.”

By making stealthing punishable under the state’s civil code, victims have a much lower burden of proof than if their perpetrators were being charged criminally. “That really helps victims and gives them a tool to hold those accountable who have violated them, and oftentimes jail is not necessarily the answer, and not something someone who has been violated wants to see as an outcome,” Neely said.

Garcia introduced her first stealthing bill around the same time Alexandra Brodsky, then a Yale law student and now a civil rights lawyer, published a paper about the practice, in which she told the story of Rebecca.

Brodsky interviewed multiple women who had been stealthed and found common threads in what they told her.

“[A]ll of the survivors experienced the condom removal as a disempowering, demeaning violation of a sexual agreement,” Brodsky wrote. Several of the women who had also been raped ranked stealthing as a lesser violation but said there was a clear connection. One described it as “rape-adjacent.”

In her research, Brodsky also discovered online forums in which men bragged about the practice and shared tips about how to do it without getting caught. One participant lamented “condom watchers,” or partners who paid close attention to make sure one was used and kept on, because the protection prevented men from breeding. Another asked whether sexual partners of “stealthers” deserved to be impregnated.

“Yes, they deserve it,” someone replied. Another agreed, saying, “[T]hat’s how god created this universe, we are born to do it.”

Garcia called such forums “disgusting.”

In February, Brodsky told The Post that legislation like Garcia’s bill could help stealthing victims.

“I think law, at its best, can express a community norm and how we should treat each other,” she said, adding, “I do think a lot of survivors would find affirmation in the fact that this state legislature agreed what happened to them was wrong.”

Paulina Firozi contributed to this report.