Various sources are reporting that President Obama has twice in recent days made reference to "his sons." Articles making this report have referred to it as "mistakenly" but it might be something else. What if first lady Michelle Obama is expecting a son? Not impossible at age 48, but somewhat unlikely.
On the other hand, as academics like to say, he may already have sons. These would have other mothers, and would be unacknowledged, at least in public. More for the conspiracy fans to enthuse about, right?