virtue exhabitionist

When a person bring up a subject that isn't affecting them in any way what so ever, in public, to show that he/she/it is on the side of good and therefor a good person. such as animal rights being violated, or anti-pedophilia, or anti-vandalism.
veryone probabely have the same idea already but you need to get the comfirmation that you are indeed "good" for having them, thus bring the subject up or express your opinion on the matter.

John: I read in the local paper that they busted a pedophile ring last weekend.
Mary: So close to us? That is scary!
Susan: I think pedophilia is horrible.

John: What the fuck Susan? Really? Is it? Good god, you are such a virtue exhabitionist.

Virtue brag

Bragging that one voluntarily exercises self restraint in the face of temptation, or takes less than one can out of moral purity or other lofty sensibilities

Tom is virtue bragging about how he paid more for his new yacht because it has more efficient fuel use and doesn't pollute the environment as much.