Seamus's instinct was to wrap his arms around Dean's suddenly-available waist as hie wiggled - so he did, being careful to approach from directly in front of Dean so he wouldn't feel ambushed. "All the cake?" he asked, raising an eyebrow when he let Dean go. "I did not say that. One cake. Just one." He held up a finger to be utterly clear about this point, but he was grinning nonetheless.
"It's not so bad," he agreed. "Thank god your name is 'Dean'. I could not fool Bones or... cub." It felt weird using his nickname for Dennis when he wasn't around, but both 'Dennis' and 'Creevey' were off limits right now.