YARMOUTH – Same-sex couples in Maine have been advised to wait before heading to Massachusetts to wed now that Gov. Mitt Romney has decided not to honor marriages there that would be illegal in the couple’s home state.

Massachusetts on Monday became the first U.S. state to issue marriage licenses to same-sex couples. But Romney has said he will enforce a 91-year-old law that has left many same-sex couples in Maine waiting in limbo.

Pat Peard, a Portland lawyer who is a member of the board of directors of Gay & Lesbian Advocates & Defenders in Boston, has offered legal advice to couples.

“I’ve given them fairly cautious advice about whether they ought to be running over the border,” Peard said. “It’s been frustrating for people to finally have their rights in sight and then be told that, because of a technicality, they should probably wait.”

Some gay couples from Maine are making wedding plans anyway.

Ginny Purcell, 45, of Yarmouth and her partner made an appointment to apply for a marriage license Tuesday in Provincetown. Their wedding ceremony will be held in Boston on May 31.

Purcell expressed disappointment in Romney’s resurrection of a law that for 27 years the state told local officials not to enforce.

“It’s an up and down feeling,” she said. “As a couple, you just want to plan things. And it’s hard.”

Peard said she can empathize with couples who call her office for legal advice. She and her partner also feel stymied.

“We’d love to go and get married. But I certainly can’t go down there and perjure myself,” Peard said.

GLAD, the advocacy group that led the fight for gay marriage in Massachusetts under the leadership of Portland lawyer Mary Bonauto, is warning couples not to get married under false pretenses.

Some Massachusetts clerks plan to ask couples for proof of residency. Only Provincetown, Somerville and Worcester will not require applicants to sign forms saying that they live in-state or intend to move there.

Officials in those three communities say they are not violating the law because applicants will have to sign a form that states they have reviewed a list of impediments to marriage in their places of residence and have not found any.

The maximum penalty for lying on a marriage application in Massachusetts is $100. Town clerks who buck Romney’s edict also could face fines and jail time.

Peard said most gay couples who want to get married are not making a political statement, and that is one of the reasons she is advising them to wait.

“We’re not talking about going down and buying a car. We’re not talking about buying a TV. We’re talking about getting married,” she said.

If Maine couples wed in Massachusetts, their licenses will not be valid at home. But members of the gay community say they are optimistic the environment here will change.

“I’m hoping that the culture is in the midst of a shift,” said the Rev. Bill Gordon, a gay pastor of Northern Lights Metropolitan Community Church in Vassalboro. “Things that don’t make sense don’t last.”