Donna Myers and Maria Barquero like to play roller hockey, go to the movies, go to the beach or just drive around and make up silly songs. "You bring out the best in me," Barquero told Myers one recent morning, and Myers nodded as they echoed one another, finished each other's sentences and laughed together.

"Life is just better," Myers said. "Life is just better when she's around."

On June 30, Donna Myers and Maria Barquero went to the St. Mary's County clerk's office and asked for a marriage license.

They felt strongly about the principle -- that they are in love and should be allowed to marry -- but were sorry to put the woman in the clerk's office on the spot because they knew full well the law would allow marriage only between a man and a woman. They both hate confrontation. "I don't like making people feel bad," Myers said. And Barquero added, "She was very nice about it."

But since they cannot marry, Myers cannot sponsor Barquero, who is Costa Rican, to move to the United States to build a house and a life with her in Hollywood. So they took the rejected form away with them and went on to the next step: joining a lawsuit against the state of Maryland, arguing that the ban on same-sex marriage violates the state Constitution and should be overturned.

Attorneys for the American Civil Liberties Union and Equality Maryland are representing nine gay couples -- and a man whose partner died not long ago -- in a suit that says current law violates the equal-protection clause in the state Constitution. The plaintiffs point to differences in the way same-sex couples are treated when making medical decisions, paying taxes and getting health benefits, among other issues.

Evelyn Arnold, clerk of the Circuit Court for St. Mary's County, declined to talk about the case and referred questions to the Maryland Attorney General's Office. J. Joseph Curran (D), the attorney general, said in a written statement that, given other cases around the country, the lawsuit did not come as a surprise. He said he would defend the existing law, which he believes unambiguously excludes gay couples in its definition of marriage.

Legislators debated the issue this spring, when proposals to outlaw same-sex marriage were defeated in committee. Gov. Robert L. Ehrlich Jr. (R) has said repeatedly that he would not support same-sex marriage, and many legislators who support domestic partnerships balk at the idea of the government changing the definition of marriage.

Last week, a proposal to amend the U.S. Constitution to ban same-sex marriages -- a measure that President Bush strongly supported -- failed to muster a majority of votes in the Senate after four days of debate. State legislatures around the country have been grappling with the issue as well.

Curran's statement said the courts are an appropriate forum for deciding the issue.

David Rocah, a staff attorney with the ACLU of Maryland, said: "It's important that people see this as affecting real people in ways that I think everyone can understand. You don't get that in abstract political debate. That's one of the things that lawsuits do in this society."

This lawsuit cannot directly solve all of Myers and Barquero's problems because their most immediate barrier comes from federal immigration law.

But it is a step, they say, and an important one. In the meantime, the two women, who have been dating since 2002 and close friends since 1999, have been bouncing back and forth between countries on short-term tourist visas. Barquero, 35, works for a Costa Rican tourism company, and Myers, who is 29, writes for a Web site from home in Southern Maryland.

They look very different -- Myers has short brown hair, pale skin and freckles; Barquero is tiny, with hair smoothed back into a twist, and expressive dark eyebrows -- but they both love family, sports and laughing.

They laugh a lot, at Barquero's corny jokes or Myers's dry comments. They laughed about Barquero's lifelong crush on Olivia Newton-John -- Barquero had a poster of her when she was a little girl, a rare treasure in Costa Rica, and loved it so much she sprayed perfume on it. "Her face melted off," she said, both of them giggling. "I had to do reconstructive surgery with a pen."

One of their road trips was to Atlantic City to see the singer perform. "She was very cute," Myers said of the star-struck Barquero. "I spent half the time watching Maria, half the time watching Olivia Newton-John. She was so happy."

Their families have been supportive, the women said, both of their relationship and their decision to join the lawsuit.

They are not sure how the lawsuit will be received in St. Mary's County, with its strong Catholic roots and traditional concepts of marriage and family. Many St. Mary's residents have strong opinions about the sanctity of traditional marriage as a cornerstone of family; some have put bumper stickers on their cars that say "Marriage = man + woman."

Myers said most people they have talked to in St. Mary's have been sympathetic. "Even though people are conservative here, they understand when we explain it," she said.

"People are fair," Barquero said. "It's not about attacking anything."

"It's not about destroying anything," Myers added.

"It's about being able to live our life and be happy," Barquero finished, holding Myers's hand in both of hers.

Myers thought about it a little. "I imagine we will . . . hear some bad things" as word spreads. She once thought she did not care what other people thought. But now she is seeing just how much other people's views can change her life. "I do hate confrontation," she said, "I'd probably go cry." She laughed a little and pulled off her little wire glasses to wipe her eyes. "I'm already starting."

Barquero reached for her hand again. "It's okay," she said. "It really is."

Maria Barquero, left, and Donna Myers play with their dog Andy at the home of Myers's family in Hollywood.