WASHINGTON — When the jubilant couple were wed in June, they exchanged personalized vows and titanium rings, cheered the heartfelt toasts and danced themselves breathless. Then, as the evening was winding down, unexpected questions started popping up.


One after another, their guests began asking: Are you going to have kids? When are you going to have kids?


Tom Lotito and Matt Hay, both 26, could not help but feel moved. They never imagined as teenagers that they would ever get married, much less that friends and family members would pester them about having children.


“It’s another way that I feel like what we have is valid in the eyes of other people,” said Mr. Hay, who married Mr. Lotito in June before 133 guests.


As lawmakers and courts expand the legal definition of the American family, same-sex couples are beginning to feel the same what-about-children pressure that heterosexual twosomes have long felt.


For some couples, it is another welcome sign of their increasing inclusion in the American mainstream. But for others, who hear the persistent questions at the office, dinner parties and family get-togethers, the matter can be far more complicated.


Many gay men had resigned themselves to the idea that they would never be accepted by society as loving parents and assumed they would never have children. They grieved that loss and moved on, even as other gay men and lesbians fully embraced childless lives. So the questions can unearth bittersweet feelings and cause deep divisions within a couple over whether to have children at all, now that parenting among same-sex couples is becoming more common.


The process can be also daunting logistically and financially, as would-be parents wrestle with whether to adopt or use a surrogate. And once they have children, many same-sex couples still endure the inevitable criticism — spoken or unspoken — from those who remain uncomfortable with the notion of their being parents.


But support for same-sex parents is growing steadily among Americans. A Pew Research Center survey conducted in July and released last week found for the first time that a majority of people surveyed — 52 percent — said that gay men and lesbians should be allowed to adopt children, up from 46 percent in 2008 and 38 percent in 1999.


The shift in public opinion and the simple question — Are you having children? — is nothing short of a marvel to some gay men, perhaps even more so than to lesbians, for whom giving birth has always been an option.


Greg Moore, 62, a retired corporate manager in Fort Lauderdale, Fla., shakes his head with wonder when he sees young male couples chattering about their toddlers. That possibility seemed hopelessly out of reach when he and his 74-year-old husband, who have been together for 44 years and married in 2008, dreamed of having children. “Gay people didn’t have kids,” he said wistfully. “Straight people had kids.”


Popular culture is helping rewrite that script. Gay men who have children, or are considering having children, are becoming increasingly visible on network television. In “Modern Family,” the nation’s most popular television show, the couple Mitchell and Cameron considered adopting a second child this past season. In “Scandal,” a new ABC series, a middle-aged White House staff member groused about his partner’s desire to adopt a baby from Ethiopia. And this fall, a new NBC sitcom called “The New Normal” will feature a gay couple and their surrogate.


The shift is also reflected in census data. Between 2000 and 2010, among same-sex couples raising children, the percentage of couples with adopted children increased to 20 percent from 9 percent, according to an analysis by Gary Gates, a demographer at the Williams Institute at the University of California, Los Angeles. (Most same-sex couples with adopted children are lesbians, but gay men make up a growing share, accounting for nearly a third of such couples in 2010, up from a fifth in 2000.)


“The definition of family is unquestionably evolving,” Dr. Gates said.


But he also noted that many Americans remain deeply opposed to gay parents raising children. Same-sex couples are explicitly prohibited from adopting in two states — Utah and Mississippi — and they face significant legal hurdles in about half of all other states, particularly because they cannot legally marry in those states. And some religious leaders have refused to provide adoption services to gay couples.