Gassy drink

Clarence went to Vivo GV to catch "Dragon Hunters" with his childcare teachers and classmates today. When he got home, he was very happy and told me about the movie.
Me: did you eat popcorn?
Clarence: yes.
Me: what did you drink?
Clarence: gassy drink! I like the gassy drink.
Oh dear, all along, we have been trying not to let him take carbonated drinks and tell him he won't like the drink. But now, he tells me he likes the gassy drink.