You're Pen!

You and Blocky had arrived to s scene of chaos. Eraser and Snowball, your best friends, are fighting at each other because they both used the purple toothbrush.

Snowball:"We all agreed the purple toothbrush was MY toothbrush!"

Eraser:"No dude, it's mine, you were using my toothbrush."

The two of you continued to watch the pair argue. Blocky and you were just stood there, looking surprised. Until you both speak up at the same time.

Blocky and you:"I thought the purple toothbrush was my toothbrush.."

You and Blocky looked at each other, mortified. Snowball and Eraser also slowly turn to look at the two of you with the same look as you and Blocky.