I have been known to talk ugly
but I do have a good sense of when and where it is not acceptable.
To me it is somewhat like scratching an itch, picking ones nose, or clipping nails in public. It is a social more that needs to be observed. I confess that any of those things bother me more than so called obscenity but I do cringe at the use of vulgarity in the presence of ladies and children.
Still, it is mystifying that the word shit is class X vulgarity and the word excrement is acceptable for polite company. The latter word invokes nothing that makes it more preferable to me. The same goes for the many euphemisms for body parts that are more or less acceptable.
Probably my greatest failing is far too often asking god to damn this or that regardless of where I am. :)