a difference of opinion among the various Christian denominations about whether Mary remained a virgin for the rest of her life, or whether she had other children (with Joseph) after the birth of Jesus.

For Catholics and others who think Mary remained a virgin for the remainder of her life, I can understand how they would find the billboard offensive (because it depicts Mary in bed with Joseph, implying that they had marital relations, which is something they do not believe happened).

But I still don't get why others are irritated by it.

"If you're looking for sympathy, you'll find it between sh*t and syphilis in the dictionary."
- David Sedaris