MIAMI BEACH, Fla. -

Lucas has two fathers who the state of Florida considers legal strangers.

"If he were hurt in the hospital, having to explain that we're the parents and be able to visit him, that would be a challenge," Thomas Gantt Jr. said.

Gantt and his partner are one of eight families that filed a federal lawsuit Wednesday against the state of Florida's refusal to recognize the rights of gay couples married in other states.

"It's the everyday stuff -- the things you don't think about when you go in to just do something as simple as getting auto insurance or taking your son to the doctors or yourself -- having people question the legitimacy of your relationship," plaintiff Sandra Newson said.

The issue is not about love, they claim, but legalities.

"We're making claims that this is discrimination on the basis of sexual orientation, on the basis of sex and it also violates the fundamental right to marry, which the Supreme Court has recognized for decades," American Civil Liberties Union attorney Daniel Tilley said.

In June, the Supreme Court overturned the Defense of Marriage Act and granted  federal benefits to same sex couples.

This lawsuit wants the courts to do the same and overturn Florida's state constitution, which does not deem gay marriages as valid or recognized.

“The only purpose of that is to try to hurt LGBT families and their children, and that is not a permissible basis for any public policy in America,” ACLU Executive Director Howard Simon said.