grammar - When would you say "I seen it."

I am not looking for explanations of why "I seen it" is wrong (though with sight there's an unfair grammatical burden that doesn't impact the other senses, whose past tense and past participle are the same - hear, heard, heard... feel, felt, felt... et cetera).

I want to know from the snoots here: in which circumstances might you actually say "I seen it."?

By way of explanation: my work sometimes takes me to places, and to people, where and to whom "I have seen it" would stand out as strange. So do I conform (let me hear you descriptivists!) or do I stand out (shout it out prescriptivists)?

---

Okay, I'm adding to my question here because there's been some negative feedback (some even calling the question "dumb"). I think it's a valid sociolinguistic question, not just one about what is said in certain dialects or which dialects use a certain expression. It's related to the issue of prestige (regular and covert), code switching, and perhaps a kind of circumstantial inversion of class aspiration.

That is, are there circumstances when you (fellow ELU members) might want to use restricted, rather than elaborated, code. Many - as evidenced by the most popular answer - flatly say "never." Others appear game to explore the idea, and there are some interesting answers that do indeed address my question.

I've chosen what I myself perceive as a fairly crass example (at least in my own speech community), one that seems to divide the educated from the uneducated. I realize this is not necessarily the case in all English-speaking regions, but it is in mine. I've chosen this because I found myself contemplating whether I myself would ever find it somehow useful to use it. To be honest, I don't think I could use it without feeling it was terribly affected.

I know it's incorrect grammatically. That doesn't mean it has no currency.

And I will not be offended if anyone considers the question crass by association (with the utterance at issue) or unenlightening and therefore chooses to simply ignore it and move on to another question.