Is it good to do that?

Whenever I see my uncle I always make a fart sound from my mouth and laugh idk why. He then calls me naughty boy and pinch ny chin and adores me and says my smile is just as sweet as he saw me when I was a small kid. He is 41 and I am 17 now. He always appreciates my height too he is 5'4(163-164 cm) and I am 5'7(170-171 cm )