The ACLU wants the owner of Arlene's Flowers and Gifts to apologize to Robert Ingersoll and Curt Freed in a letter to the Tri-City Herald.
The ACLU says the men have been a couple for almost nine years and plan a marriage in September. When they went to the flower shop on March 1, the owner told them she wouldn't provide flowers for the wedding because of a religious objection.
State Attorney General Bob Ferguson is suing the shop owner for discrimination. The complaint was filed in Benton County on Tuesday against Barronelle Stutzman, owner of Arlene's Flowers and Gifts in Richland.
Ferguson had sent a letter on March 28 asking her to comply with the law, but said Stutzman's attorneys responded Monday saying she would challenge any state action to enforce the law. Washington state voters upheld a same-sex marriage law in November, and the law took effect in December.
The state's anti-discrimination laws were expanded in 2006 to include sexual orientation.
Ferguson seeks a permanent injunction requiring the store to comply with the state's consumer protection laws and seeks at least $2,000 in fines.
Her lawyer says she sells flowers to homosexuals, but can't support a same-sex marriage.
The ACLU wants Arlene's to agree to provide flowers for gay marriages.