Being gay is not objectively wrong; it is just frowned upon in this society, and, I being a member of this society, ought to frown upon it in this society as well".
But ita OK for u to frown upon something..but if I do I am called a bigot
1. I am not a cultural relativist. The example (re: 13 year old girl) was used to demonstrate what cultural relativism says one can and cannot say; not what I believe.
2. If one has relevant, operative reasons for disapproving of something, it is both acceptable and appropriate to disapprove. Correlative to that, though, there is a duty to present these relevant, operative reasons when asked.
Here is an example:
You say: Marrying 13 year old girls is an abomination.
I inquire: Why?
You: They are 13.
I: Yeah, but why is it wrong to marry a 13 year old.
You: They are 13.
Not only does "You" fail to provide a relevant, operative reason; "You" fails to provide any reason, since he simply circles back to his original proposition.
Now, here is another example:
You: Marrying 13 year old girls is an abomination.
I: Why?
You: Well, I think it constitutes rape.
I: Why would you think that?
You: Well, the vast majority of 13 year olds do not yet possess the rational capacity to give consent. And, rape is sexual intercourse without consent.
I: Yeah, you know what, you are right; this could be a case of rape. And, I agree with you that rape is an abomination.
Now, there is still a generalization problem in this example; however, you ought now to get the gist of what relevant, operative reasons are (and, of course, there would have to be a further argument as to why rape is an abomination; this argument includes notions such as autonomy, physical security, the psychology of fear, etc.)