photo Green Day frontman Billie Joe Armstrong has remained a fixture in the press throughout his storied career over the past few years, with much of that attention revolving around his time in and out of rehab...but not today! A seemingly irritated Armstrong took to his instagram account, posting a picture of Psy with this caption: “This dude is the herpes of music. Once you think it’s gone, it comes back. #herpes, #flareup and #pleasegoaway." At the moment, the post has garnered over 21,360 likes and over 2,100 comments. When Psy sat down with Fuse to issue an informal response, the international K-pop star asked, "What is herpes? Is it like a disease?" Fuse then explained before asking what he thought of Armstrong's comment. "I kind of like it, it's cool. I should say something to him. He's saying I'm like herpes, [I] keep coming back ... I think it's really cool, and I appreciate that. Thank you." It's unclear if Psy is joking or just doesn't quite understand Armstrong's dig, but either way, he's not losing sleep over it! What do you think of Armstrong's comment and Psy's response? Is this a real rivalry, or friendly fire?