I'm offended by gays being gay in public. i know i'm not open minded in a few areas and that is one. i wouldn't even be comfortable around them holding hands much less them dissing marriage something that i believe in. I think the park was in the right to have them turn the shirt inside out. I also believe they would do it is there was a naked woman on a shirt. something that might offend a nudist. obviously i know that i will see things that i don't agree with and i will see these things also with my kids. it is my job to teach them what is right and wrong.
i probably would have pointed at them laughed and took a picture. i wouldn't care if i offended them since they didn't care who they were offending.
i also think it is ironic that the shirt one of them was wearing could be offensive to some people but they are worried that they were offended.