Phineas tightened the screw. While they had drills, they owned more drills than they had friends, he was using a plain, old fashioned screwdriver. It made it easier to look completely focused on the task instead of the hushed conversations behind you that way. Even if calling them hushed was a stretch. Even when they were trying to whisper, the Fireside Girls voices carried when they were only ten feet away.

He'd still know what they were talking about if he couldn't hear it. Isabella wasn't exactly subtle, and he wasn't stupid. Or blind. Or deaf.

Ferb thought he should either confess to her or just let her down and put an end to the charade. While Phineas didn't think his brother's advice was wrong, it was coming from Ferb after all, he didn't think he could bring himself to do it. He didn't know how to do it without hurting her, whether by breaking her heart or by letting her know he knew and had been lying by omission.

It wasn't like he'd picked up on her crush from day one, he'd spent a long time brushing the little signs off because she couldn't possibly feel like that about him. His head was a triangle, that couldn't be attractive. Once he stopped denying it, it was easier to see the ways she showed it. And he hated that. He hated that she'd bend over backwards for him, and he did his best to ignore it so he wouldn't be too tempted to tell her to knock it off. He wanted her to help him because she was one of his best friends, not because she was trying to please him.

Phineas liked her better when she acted like herself. 

The screw tightened to the point that he couldn't turn it anymore no matter how much he tried. He pretended it was still turning.

Sometimes, he'd slip up and call her cute or something. He thinks it makes her happy when he does, but he's not sure. He knew it would make her happy if he just went on a date with her without inviting Ferb along. But then he'd either have to act like it wasn't a date or let her know he knows it's a date and then she might think they're dating which is something he doesn't want.

If movies taught him anything, it's that dating your best friend either ends in a happily ever after or in a ruined friendship. The later was too big of a risk. He wouldn't be able to deal losing Isabella any more than he'd be able to handle it if he somehow lost Ferb. Just thinking about the possibility sent a shiver of dread through him.

If Isabella stopped hinting around and told him point blank or if he saw he was losing her anyway, he'd come clean, but until then, their twisted formula worked, or at least kept everything in balance. It wasn't a kind way to do it, it was selfish even but, as he finally turned away from the screw to watch his friends have fun as they put his Big Idea into action and Isabella met his eyes to give him a small smile, he really couldn't make himself care.