A same sex couple filed a lawsuit against Nevada on Tuesday, alleging that the state's ban on same sex marriage violated the Equal Protection Clause of the U.S. Constitution.

Beverly Sevcik, 73, and Mary Baranovich, 76, are being represented by Lambda Legal, as well as O’Melveny & Myers LLP and Snell & Wilmer LLP.

"We’ve been together for almost 41 years," Sevcik said. "We’ve seen each other through thick and thin, in sickness and in health. After four decades of sharing a life together, all we want is to show our love for each other as other couples do, through marriage."

Nevada's Protection of Marriage amendment, approved by 67 percent of voters in 2002, states that marriage is only between one man and one woman. The state provides gay and lesbian couples with nearly all of the state law rights and responsibilities afforded to same sex couples, but withholds the designation of marriage.

The lawsuit alleges that the marriage ban causes "serious and irreparable" harm to same sex couples and their children because it treats them like "second-class citizens who are undeserving of the legal sanction, respect, and support that different-sex spouses and their families enjoy."

The same sex marriage ban violates the Equal Protection Clause of the Fourteenth Amendment because it discriminates on the basis of sexual orientation and sex, the lawsuit states.

“Nevada’s prohibition on marriage for same sex couples serves no legitimate state interest, a fact the state even acknowledged by creating a parallel, but less respected, legal status of registered domestic partners,” said Lambda Legal Staff Attorney Tara Borelli. “The ban on marriage equality brands these loving couples and their children as second-class citizens, and encourages private bias and discrimination.”

Seven other same sex couples are plaintiffs in the case, Sevcik (Se-vik) & Baranovich, et al. v. Sandoval, et al.