Well, first fanfic. Hope it's good. At least it has good grammar…
Disclaimer: Please note that I do not own Phineas and Ferb. I'm pretty sure that I'm not a guy.
Perry wasn't sure how he was supposed to react to this. Life had been normal as it could get for the platypus, until this happened. They weren't supposed to know, much less remember that he was a secret agent! It was ten at night, when the boys suddenly shot up, glanced at each other, and looked at Perry. He had no idea what was happening, so he just put up his typical façade, and hoped that it was nothing. Of course, that façade completely dissolved when Phineas whispered, "Agent P?"
By that point, Perry was frozen in shock. Phineas and Ferb knew his secret! There was nothing he could do other than stare at them. "Perry, we remember now. We remember the Second Dimension. You can drop the act already."
Wait a minute, how did they regain their memories?! Oh, the amnesia-inator probably messed up. It was, after all, Doofensmirtz's design. Maybe he should stand up now… No, if he did that, they'd know for sure that he was a secret agent! It would basically guarantee that he would be relocated! He didn't want to leave his boys…they weren't just his cover, they were his family too! "Perry, you're not exactly fooling us. Your eyes are focused."
Dang it! He must have accidently dropped his act due to the shock! Well, since they remembered and he just gave them proof, there really was no point to acting dumb. Perry stood on his hind legs and stared at his owners. He then proceeded to put on his hat and get a notebook. "You guys know what will happen due to you knowing my identity, right? I'll have to leave."
Perry definitely expected their reactions to this. The brothers got up and hugged Perry, and Phineas vehemently denied any need for Perry to be relocated. After all, what Major Monogram didn't know wouldn't hurt him, right? At that, Perry smiled, though he knew just how mad the Major would be when he found out (there was never an "if", just a when). Perry got out the notebook again, and wrote that Monogram would probably relocate Perry and use the amnesia-inator if he wasn't immediately informed.
Despite writing this, Perry never made a move towards the door.