Gay Rights and the Race Analogy

Here is a very good piece by John Corvino (who, for what it's worth, is gay and a leading intellectual regarding things homosexual). Excerpt:

Consider a very different case: Suppose I’m a photographer who can’t stand children. You want me to take pictures at your child’s birthday party — there will be games and clowns and other things I find annoying — and I decline.
No serious person would suggest that the law ought to penalize me for age discrimination — but why? Before answering, consider two more cases:

Case 2: I’m a photographer who disapproves of homosexuality; the mere thought makes me uncomfortable. You try to hire me for your lesbian wedding; I decline.

Case 3: I’m a photographer who disapproves of miscegenation; the mere thought makes me uncomfortable. You try to hire me for your interracial wedding; I decline.

Now, is the lesbian wedding case more like the birthday party case or the interracial wedding case?