English-speaker here (UK) - just to let you know that Yay! is very definitely used in a non-ironic fashion all the time as a light-hearted, perhaps slightly jokey, expression of delight. In text, and sometimes even in speech.<p>I can &#x27;calibrate&#x27; a Yay to indicate a negative sentiment based on context, but it&#x27;s a bit jarring and not even very strongly negative. Examples like &quot;Two more weeks of working overtime. Yay&quot; is obviously a negative use <i>but</i>, to me, that&#x27;s you indicating disapproval of a fairly trivial inconvenience or annoyance in a rather light-hearted way. If you really disliked something I&#x27;d expect a more direct statement like &#x27;damn it&#x27; or your whatever your chosen flavour of profanity.<p>The idea of Yay as a general meme for negativity is very jarring, at least to this native reader, and I&#x27;d really struggle to imagine it ever catching on as a result. Hope you found this perspective useful!