As soon as he heard the opening line to what Heroin had to say Grunge knew it wasn't leading to anywhere good.
The very first line had him shocked; no, actually, he'd had no idea he even had a foot in Heroin's heart. His people, his genre, his... HE had been addicted to Heroin, his very nature was (now) inescapably knotted into a dependence on, a worship of, a desire for heroin. Why that would have given him any sway over Heroin's heart? Not after Kurt. Not after he'd left. He'd thought he'd has his chance and fucked it (and had been killing himself over it ever since... he'd never had another lover since the drug) and that line brought that awful hope bobbing back up into his trachea but he once again shoved it back down because he knew better than that.
And that was something proven in the next minute.
He sighed long and heavy as Heroin said the words that broke the thready wispy maybe hope between them, broke it and threw it to the floor and then jumped up and down on it until there was nothing left of it but a smear on the ground. "Well..." he stopped to light a cigarette because although he knew deep down that things had died between them after Kurt had literally likewise died between them, hearing it said still hurt and he needed something to keep his hands busy so that his very-ex-lover wouldn't be able to see his hands shaking, needed the warmth to try and melt the chill inside him a little. He lit up, exhaled smoke and shrugged, shaking the match out. "... thanks for telling me." Yeah he was glad he'd kept his shades on now and he was never, ever listening to the fucking Sneaker Pimps ever again.