Is it okay to feed my dog chocolate truffles?

my mom said not to but he looks so cute eating them i have been feeding him imported belgian chocolate truffles for the past 2 and a half hours and he looks happy so he is probably okay but i am not sure because i heard that chocolate is bad for dogs should i keep giving them to him i place it in the palm of my hand and he gently eats it i can feel his whiskers brush against my fingers it is the cutest thing i have ever seen