A Vongola fire butt weapon. Ridiculous but totally not. If their boss's tutor is the worlds greatest hitman, and also an infant, and his best method of training, his pupil is shooting him in the head... it's not unreasonable to think there could be some Vongola style weapon that entails fire-butt shenanigans.

Where the lighter, cigarettes, and dynamite go is a secret that Gokudera will never share. A mafia man is entitled to his mysteries.

"So you heard me but didn't listen! No cat ears of mine are being touched. Actually! Just don't touch me- Ughhhh," Have a dramatic groan and a shove, Yamamoto.