Something tells me I'm going to regret this, but I'll try to explain. I've no objection to the word "ain't", grammatically or otherwise. The word has the potential to add emphasis to a comment.
Think of someone standing up and saying "it ain't happening" --- one gets the message that he's serious. Sen. Kennedy from LA is a master of this technique. You just know when he's going add "ain't" to his closng statement ----- like a fist punch making his ridicule all the more powerful. He doesn't do it all the time. He saves it, and his timing and impact, thus far, have been impeccable.
But, your use of "ain't" is exclusive ---- and this is unusual and what has caught my attention. So, I figured there had to be a backstory to this. And let's face it, my friend, your backstories are frequent and colorful --- from standing naked in front of your open refrigerator in the middle of the night, to sharing the wonders of life with your lady friend outside under only a tarp, to fixing a 30 year old pick-up truck with a matchbook cover and spit.
I was simply wondering about a backstory for "ain't". I wasn't poking, I was prodding --- as in persuading you to tell the story. I was expecting something along the lines of: "First, let me tell you about the time I didn't say "ain't" 
But, you've explained there is no story, that this is simply who you are ---- and I, for one, would not try and change that for the world.
Enjoy your Sunday @roamer_1 See you around campus 
@Right_in_Virginia Well now, darlin... Your talent has left me at a quandry....
Part of the fun with you is that can never quite figure you out... Your ability at word-smithing allows me but two paths:
Either that reply is a beautifully constructed and well thought out dodge - playing to my character, and my love of telling my 'colorful tales' - laid quite deliberately to snag me in the very root of who I am... To walk off from the game, at last, scott-free... Held inviolate...
Bearing in mind of course, that such a machination would be an overkill by an order of magnitude - and unnecessary since I had already indicated that any insult was defused. However, still a sturdy option in your repertoire, worthy of your 'bag of tricks' and ease of play...
Or that was quite likely one of the greatest compliments of my life, spent in passing, with nary a crown thrown.
If it was the latter, then I thank you for the kindness, truly.
However, I will suppose it to be the former, through no fault of your own - because if it were the latter, it would give me a fat head - And we both know I need no more of that.
Likewise, enjoy your afternoon.
And we should end it here, before
@DCPatriot comes along to yell, "get a room!"
