An “ex-gay” group has filed a brief urging the Supreme Court not to rule in favor of gay marriage because being gay is a choice.

The Supreme Court will hear oral arguments in two cases related to marriage equality in March. One case, Hollingsworth v. Perry, challenges the constitutionality of Proposition 8, California's 2008 voter-approved constitutional amendment limiting marriage to heterosexual couples. In Windsor v. United States, a lesbian widow is challenging the Defense of Marriage Act (DOMA), which prevents the federal government from recognizing her marriage to another woman.

In its friend of the court brief filed on Friday, Parents and Friends of Ex-Gays & Gays (PFOX) asserts that being gay is not an immutable characteristic.

“PFOX appears as amicus to address the purported immutability of homosexuality, which is relevant to whether this Court should declare that sexual orientation is a new suspect class,” the group wrote.

“The issue is important because a finding that sexual orientation is immutable could lead this Court to declare it a 'suspect class' for purposes of the Equal Protection Clause, which is unwarranted. Such a declaration could improperly subject state laws or state Constitutional provisions like Proposition 8 and Congressional Statutes like DOMA to 'strict scrutiny' rather than the existing legally appropriate, 'rational basis' review.”

To support its argument, PFOX included the personal stories of 4 people who decided to no longer be gay: Richard Cohen, the founder of the “ex-gay” group International Healing Foundation; Alan Medinger, the deceased founder of the “ex-gay” ministry Regeneration; Kristin Johnson Tremba, the author of Sexual Wholeness in a Broken World; and Brenna Kate Simonds worship leader of the Boston-based “ex-gay” ministry Alive in Christ.

The Supreme Court is expected to rule on the cases in June.