full-contact vacuuming

When Rachel vacuumed the living room today, Matthew wanted to vacuum too. Rachel told him he could have a turn after Mama. Matthew couldn't wait, though, and got his toy vacuum to "help" -- or so I thought. He really wanted to play FULL CONTACT VACUUMING. Whenever Rachel made a stroke with the vacuum, CRACK he would ram into hers from the side. CRACK. CRACK. CRACK. This is the first time he has done this. I sincerely hope he doesn't make it a habit.