A gay couple is suing a Colorado baker over his refusal to sell them a wedding cake.

Last summer, Jack Phillips, owner of Masterpiece Cakeshop in Lakewood, Colorado, refused to consider baking a cake for Dave Mullins and Charlie Craig, who married in Provincetown, Massachusetts and held a reception in Denver.

The American Civil Liberties Union (ACLU) filed a complaint on behalf of the couple with the Colorado Civil Rights Division (CCRD). A CCRD investigation concluded that Masterpiece Cakeshop broke the law by discriminating against the men. Last week, the Colorado Attorney General's office filed a formal complaint. A CCRD hearing is scheduled to take place in September.

“We were all very upset, but I was angry and I felt dehumanized and mortified,” Mullins told the AP.

The ACLU claims that Masterpiece Cakeshop has refused a wedding cake for two other gay couples. Both have submitted written affidavits in the case. According to one of the couples, Phillips told them he would not provide cakes for the weddings of gay couples the same way he would not provide cakes for pedophiles.

Last year, Phillips told CBS affiliate KCNC-TV that he would rather shutter his shop than bake a wedding cake for a gay or lesbian couple.

“If it came to that point, we would close down the bakery before we would compromise our beliefs, so that may be what it comes to. We'll see,” he said.

But the cake shop owner went on to say that it's nothing personal: “If gays come in and want to order birthday cakes or any cakes for any occasion, graduations, or whatever, I have no prejudice against that whatsoever. It's just the wedding cake – not the people, not their lifestyle.”