A scruffy man, tanned and good-looking, dressed in an old leather jacket and snug jeans, is on a motorcycle zipping through a neighborhood near you. He’s a restaurateur into “local” everything, a man whose produce vendor is one among many sexy women who want to hook up with him. He was also, years ago, a sperm donor who, unbeknownst to him, achieved reproductive success.

Meet Paul, who is about to encounter the California lesbian couple who each became pregnant with his sperm. In a moving, at times ambivalent and, despite its attempts at realism, largely fantastical exploration, the new hit movie The Kids are All Right probes the emotional fall out after eighteen-year-old Joni makes a phone call that results in a first-ever meeting between the two teenagers, their biological father (played by Mark Ruffalo), and the mothers (Annette Bening and Julianne Moore) who raised them.

The movie is rich on particulars and complexity; there are no stock characters here. The lesbian mothers are sympathetic, funny, and attractive, but have their faults. The daughter is a classic overachiever who wants to protect her mothers. The fifteen-year-old son is a jock with feelings, at ease in a world of women but not one of them. If you came looking for a heavy-handed defense of gay marriage or a commercial for gay families, all happy-go-lucky behind their white picket fences, you won’t find it here.

What you will find is a sometimes searing exploration of the raw emotions at stake when women who never intended for their children to have a father suddenly find a father in their lives. “The plan was to limit the involvement,” says one, desperately. “He’s their biological father and all that crap,” says the other. “And it’s really sh---. Like we’re not enough or something.”

The film also exposes the task that confronts children when they meet their sperm donor father, for the first time, once their childhood is largely over. On their way to meet Paul, protective Joni warns Laser, her brother, “I just don’t want you to have big expectations.” Later, Laser asks Paul, “How much did you get paid?” Paul admits, “I got paid 60 dollars a pop.” Laser flinches, and so do we, at a child’s bald confrontation with the cold facts of his commercial conception.

Despite the attempts at realism, the movie is a fantasy. To begin with in real life, these kids would not have found it so easy to find their sperm donor father. And it’s equally unlikely that he would resemble the easy-going, available Paul.

The movie implies that the children have an identity release donor, a concept pioneered by the lesbian-friendly Sperm Bank of California in the 1980s. The policy allows children to learn the identity of their sperm donor when they turn eighteen. Once Joni makes the phone call, in the blink of an eye Joni, Laser, and Paul are sitting at an outdoor table, bathed in sunlight, playing get-to-know-you.

For most donor conceived persons, this is the stuff that dreams are made of. Throughout its long history (the first recorded case of donor insemination in America took place in Philadelphia, in 1884), sperm donation has nearly always been an anonymous transaction. Male infertility was a source of shame, and going outside the bonds of marriage to reproduce with the aid of modern medicine was thought best kept a secret for the sake of everyone involved.

Even today, with greater societal openness about sexual matters, still most donor offspring have not even been told the truth by their parents about how they were conceived, and the law continues to allow anonymous donations of sperm and egg. If young people do find out they were conceived through sperm donation, they have almost no hope of finding their biological father.

While lesbian couples and single women who use sperm donation have tended to be more open about how the children were conceived (the obvious lack of a father does raise the question), they often use anonymous sperm donors, too. Some lesbian women fear that a non-anonymous donor might someday challenge them for custody of their children. Others have other reasons, recently highlighted in a publication by COLAGE, a support and advocacy organization for children of gay and lesbian parents and their families.

One lesbian mother says she and her partner chose an anonymous sperm donor because “we didn’t want to triangulate our parenting or form a life-long negotiated relationship with anyone else but ourselves.” Another says she had a “fear that our child [would] at some point wish for a father and embrace a relationship with the donor seeking this, in ways that harm[ed] our child or displace[d] our parenting relationship.” Another says, “we wanted [our children] to have 2 parents who were moms only.”

Granted, Joni and Laser have an identity release donor. But in these cases, the sperm banks only promise to provide their most recent contact information for the donor to the child who has reached age eighteen. It’s up to the sperm donor to keep his contact information updated. If you do locate him, he probably won’t live a short motorcycle ride away, as Paul does. He could live in another part of the country, or another part of the world. He probably now has a family of his own (in the movie, Paul does not) and his wife might not be thrilled about him meeting his other children. Or he could be dead.

The film also implies that Joni and Paul are the only children resulting from Paul’s donations. The fantasy depends on his being able to give them his undivided attention (and so it is also useful that Paul is single). In the United States, there are no limits to how many children can be conceived with one donor’s sperm. The American Society for Reproductive Medicine offers merely a professional recommendation that one donor father no more than 25 children.

If a man donates at more than one clinic, there is no way to know how many children he has. Some donors have discovered they have dozens of children. One donor in the United Kingdom has more than sixty. If other children conceived with Paul’s sperm start coming forward, how much of Paul will there be to go around?

But for the moment, let’s accept the premise of the movie. The kids have found their sperm donor biological father. Now what? Ambiguity reigns, and it’s up to the children to make sense of it all.

The COLAGE guide is authored by a young man who was himself conceived through sperm donation and raised by lesbian mothers. Of the sperm donor, he says, “we must decide what this person means to us.” He notes the “challenging task of defining the relationship with your known donor.” He reassures the reader, “It is completely normal and okay to speak up about the kind of relationship you want with your donor.”

When the institution of something called fatherhood falls apart, this is what happens. We leave children to define the relationship of themselves to their fathers. Children must decide what this person “means” to them. They should “speak up.”

Some might be able to do this. But what about the others? What about the ones who are not gifted with emotional intelligence—the ones who aren’t skilled at negotiating ambivalence and speaking up about their own needs in the face of their parents’ tender feelings?

And what about those whose sperm donors have no interest in being fathers? In the COLAGE guide, one young woman says, “My donor doesn’t seem to be particularly into the whole father thing with me, and it caused me quite a bit of pain trying to get him to be.” Another says: “I grew up having certain expectation of what roles my [sperm donor] . . . would play in my life and when [he] didn’t fulfill those expectations, I was hurt.”

A recent study of donor-conceived adults, reported in My Daddy’s Name is Donor, found that, overall, donor offspring are hurting more, more confused, and more isolated from their families compared to those who are adopted or raised by their biological parents. Two-thirds say, “My sperm donor is half of who I am,” even though few know who that donor is. They are significantly more likely than other children to be struggling with problems like substance abuse, delinquency, and depression.

In The Kids are All Right, the actors benefit from a script. In real life, there is no script for these kids. It’s up to them to figure everything out and make the best of it. The person whom a child rightly considers her father is a man who might well believe—probably does believe—that he is just a “donor.” That is not—at all—all right.

Elizabeth Marquardt, the director of the Center for Marriage and Families at the Institute for American Values, is co-investigator of the ground-breaking My Daddy’s Name is Donor, which reports a large study of adults conceived through sperm donation. The report is available at FamilyScholars.org, where she also blogs.