As Tony walked into the room he could say without a doubt that he was completely shocked at what he found. Not that he was unfamiliar with the Starbomb album, be he never expected this.
Now Natasha and Bruce would probably both point out that he and Clint teaching Cap and Thor about classic video games is totally at fault for this situation however that could be argued at a later time.
Before him, Steve Rogers and his bestie metal armed outlaw were singing a duet, while Clint skipped around in a Link costume. Now Tony knew his beloved partner had eccentricities but this just about topped them off.
Bucky was singing the role of Link and Cap was logically "Old Man". They had just started the second part, when Tony realized how equally happy and jealous this made him. Of course Bucky made Steve happy, but the time the oldies spent together rivaled his own Steve time.
By now Clint had noticed him and had started not so subtly shooting arrows his way.
"Jesus Christ watch it Zelda!" Tony snapped not realizing his mistake. Tony was completely amused as Cap and Bucky were finishing off the last lines...
" OKAY NOW I REALLY DONT KNOW WHERE I AM..."
"HOLD ON A MINUTE LINK!"
"GOD DAMNIT OLD MAN..."
Tony honestly couldn't deny his enjoyment of this situation, until of course he remembered he had called a grown man wearing a Link costume who was also an avid video game enthusiast "Zelda". And of course, it was Clint after all, the bow set was real.
No member of the Avengers initiative would ever let him forget the day he had to have an arrow removed from his ass.