In the aftermath of the Pulse nightclub massacre in Orlando, images of two men kissing have been everywhere. Good. They should be hard to avoid.

As much as Americans pledge support for LGBT people and as frequently as we recite the “love is love” mantra, same-sex love still makes too many of us uncomfortable when we witness it firsthand. Until we believe in person—and not just on paper—that love is love, the hatred that fuels attacks on LGBT people will be alive and well.

Social media first exploded with images of men locking lips under the #TwoMenKissing hashtag after Omar Mateen’s father claimed that his son had been infuriated by the sight of men kissing on a recent trip to Miami.

“Look at that,” the man who would go on to murder 49 clubgoers allegedly fumed. “In front of my son, they are doing that.”

After hearing this anecdote, first reported by NBC News, illustrator Shadi Petosky posted a collage of men kissing to Instagram. Shortly thereafter, writer and Her Story co-creator Jen Richards reblogged the collage, adding a stirring caption.

“Look at #TwoMenKissing,” Richards pleaded. “Really look. Then look inside yourself and be honest about how it makes you feel. Find any discomfort there and look at it. Examine it. Sit with it for as long as it takes to overcome.”

Her invitation to scroll through pictures of #TwoMenKissing wasn’t just intended for the kind of openly homophobic bigots who would celebrate the mass murder of LGBT people. Discomfort with same-sex PDA is shockingly common, especially given current levels of support for same-sex marriage and LGBT rights.

More people than you might think would be upset by the very same sight the Orlando killer allegedly saw. You could be one of them.

At present, over 60 percent of Americans support same-sex marriage rights, according to Gallup data.

But nearly 30 percent of non-LGBT Americans still feel uncomfortable when they see a same-sex couple holding hands, according to a survey commissioned by GLAAD for its annual Accelerating Acceptance report. Twenty-six percent said they would be uncomfortable seeing a same-sex wedding photo on a co-worker’s desk.

The data for same-sex kissing is more disheartening still.

In 2014, when support for same-sex marriage was well past the halfway point, a study from Indiana University researchers published in the American Sociological Review found that heterosexual Americans were more supportive of inheritance rights for same-sex couples than they were of same-sex PDA, particularly between two men. Sixty-nine percent of heterosexual respondents to the nationally-representative study said that a gay male couple should have inheritance rights but only 55 percent said they approved of the couple kissing not even on the mouth, but on the cheek.

"Support for legal benefits for gays and lesbians should not be conflated with favorable attitudes toward same-sex couples in general,” said lead author Long Doan in a press release. “We come to the conclusion that although heterosexuals may be increasingly willing to grant legal benefits to gay and lesbian couples, entrenched prejudice that takes on subtler forms may remain.”

In 2016, it should be horrifying that same-sex couples still cannot hold hands or kiss without fear of disapproval not just from outright bigots, but from straight people who ostensibly support their rights.

Some have speculated that Mateen himself was a closeted gay or bisexual man based on statements from Pulse clubgoers, a former classmate, and his ex-wife’s new fiancé. If that’s true, his father’s story about the Miami incident would still make sense. The American Sociological Review study found that even gay and lesbian respondents were sometimes significantly less supportive of same-sex PDA than they were of heterosexual displays of public affection.

Doan largely attributed this counterintuitive finding to “safety concerns” in the press release but, in the full study, the authors noted that “heteronormativity and internalized stigma” could help explain the discrepancy.

Simply put, it is entirely possible that a man who was deeply conflicted about his own sexual identity and radicalized by a particularly homophobic element of a religion would react badly to two men kissing within his line of sight. Gay and bisexual men—if Mateen was indeed among their number—can be homophobic, too, even if that means they fear something inside themselves.

That same fear doesn’t just lurk in the hearts of individuals; it permeates American culture as well. So pervasive is our phobia of same-sex kissing that CBS cameras conspicuously cut away from same-sex kisses during the 2014 Grammys when Queen Latifah married dozens of couples on stage. (CBS later denied that the many omissions were intentional.)And so extreme are the reactions to same-sex PDA that when ABC’s Once Upon a Time television show showed a lesbian kiss, social conservatives said that Disney was “purposefully pushing a gay agenda” with a “graphic gay scene targeting kids.”

Rhetorically speaking, that’s not a far cry from what Mateen allegedly said about two men kissing in Miami: “In front of my son, they are doing that.”

Meanwhile, it would be almost impossible for anyone—adult or child—to go a full day without seeing an opposite-sex kiss whether in person, on a billboard, in a show, at a bar, or in one’s home.

It would be as futile as it is irrational to oppose opposite-sex PDA. It’s everywhere. Maybe now is a good time for same-sex PDA to become just as ubiquitous.

In the meantime, LGBT people will keep flocking to gay bars to feel safe. Clubs like Pulse are sanctuaries where same-sex couples can drink, dance, flirt, and kiss without fear, just like straight people do almost everywhere. They are havens where PDA is welcomed instead of edited, embraced rather than condemned as a danger to children. They are places where, as Sam sang in Casablanca, a kiss is just a kiss.

The search for absolute clarity on Mateen’s personal life will continue, as it always does in the wake of a mass shooting. The FBI investigation into his terrorist ties will go on, too. But nothing we can do now will bring those dozens of victims back to life, nor can we retroactively remove the hate from Mateen’s heart.

What we can do is try to prevent history from repeating itself by working to destigmatize same-sex behavior. For many of us, that will mean looking inward and, as Richards wrote, “look[ing] at two men kissing until all [we] see is beauty and love, courage and pride.”

Some of the victims of the Pulse massacre were indeed two men who kissed: couples like Jean Carlos Mendez Perez and his partner Luis Daniel Wilson-Leon who met over a perfume counter, or Juan Ramon Guerrero and Christopher “Drew” Leinonen who will receive a joint funeral in lieu of a wedding.

Their love for each other will be remembered always in death. The difficult question that Americans must ask each other and ourselves is how we would have reacted to their love had we witnessed it in life, in full motion, right before our eyes.