Most people like the idea of a long-term loving relationship, and pedophiles are no exception. Children can never be appropriate partners, but for many pedophiles a relationship with an adult is possible. Many of us are non-exclusive -- we do have some attraction to adults.
Instead of thinking of pedophilia as a single thing or even a single dimension, here's another framework: People have two knobs of sexual (and romantic) interest, one pertaining to children and one pertaining to adults. (I addressed this basic issue in <this post>.)
If the interest in children is above zero but low and the interest in adults is high, a man (or woman) can lead a normal life. They might be unaware of their interest in children or consider it an unimportant curiosity.
If interest in adults is on the low side, sexual passion may be an issue. Today most couples have sex before they commit to each other. It's easy enough for potential partners to judge whether they can find a sex life that suits them. Is it dishonest if a pedophile is faking his interest a little bit? It's not ideal, but I think it is similar in kind to doubts ordinary people may have about their partner's attractiveness. A great many people who are well below average in attractiveness nonetheless get married, and their partners make do. Emotional bonds hopefully grow and become more important than the physical in any case.
The more complicated issues arise here for the pedophile depending on the level of the child-attraction knob. If a man (or woman) identifies as a pedophile, there is one huge question they must confront in considering an adult relationship: should they tell or keep a big secret?
If child attraction is just a curiosity for a man that he doesn't think about much, he could keep it secret the same way an ordinary person might not share some of the more embarrassing moments of their life or the identity of other people who they find really hot. For some middling levels of attraction, this can be a matter of attitude. When young teens write to Virtuous Pedophiles reporting an interest in children, we advise them to first look at the attraction they have to peers and grow it however much it can be grown. A happier life awaits if the attraction to children is just a curiosity rather than an obsession -- and one reason is the ability to enter into an adult relationship without keeping what feels like a big secret.
But of course for many pedophiles the level of attraction to children is high and unmistakable, and there is no option of spinning it as something unimportant in their mental lives.
In a dating situation, it's a fair bet that the common response to, "Uh, you ought to know, I'm a pedophile" is an abrupt end to a budding relationship. An enlightened partner would be quite the rarity. The alternative is to keep it a secret. A hybrid option is to keep a secret for a while but raise the question before a decision about marriage.
Lest you immediately scream that any delay in mentioning this shows despicable character, I'd first note that a great many pedophiles agree with you, and they simply will not consider adult relationships at all because of this. As for the others, I'd ask you to think about human frailty here. Have some gay men and lesbians entered into heterosexual marriages and stayed closeted to their spouse, especially in earlier times when coming out was far more dangerous than it is today? Have people hidden unflattering aspects of their past relationships, legal status, medical conditions or family background?
Some pedophiles might think that it's morally OK to enter a relationship with this secret, but that keeping the secret would limit their own satisfaction and trust too much. Others might think it's morally OK if they really could keep the secret, but have doubts about whether they could keep their attraction hidden for decades. Both these groups of pedophiles too will remain single.
But with all those other cases excluded, the end result is that a fair number of pedophiles do end up married. Aside from an explicit willingness to keep a big secret, another way they can end up in this situation is to have a dim awareness of pedophilia in the early stages of a relationship, but then find it growing in importance in their minds after they are married. The more that has been invested, the more appealing the option becomes of keeping a secret (I also think ethical concerns go down proportionately). I personally thought a soft spot for young girls was just a curiosity when I got married, and when I entered a long-term relationship at the age of 50, I was more aware of that attraction but still thought of it as a harmless curiosity and didn't label it as pedophilia. Both relationships ended for other reasons, and the attraction was never an issue.
Occasionally we get inquiries at Virtuous Pedophiles from girlfriends or wives who have just discovered their man is a pedophile -- usually because child pornography is discovered. Should they stay together? First, I know full well these women are a heavily biased sample. I suspect a lot of women wouldn't even consider staying and would never write to an organization called "Virtuous Pedophiles" seeking an opinion. But I note that some of them do seriously consider staying -- they know the good qualities of these men and do not see as an outsider does only a faceless image of a man with a "pedophile" sign around his neck. Several Virtuous Pedophiles members are married and their partners know of their attraction.
I hope I've conveyed some of the complexity of the situation pedophiles face in considering adult relationships. On the one hand, a great many pedophiles will not form adult relationships even if they have a sizable attraction to adults. On the other hand, some pedophiles do end up married (or otherwise partnered). In some cases their partner knows of their attraction, and in some cases he or she doesn't.