I sing in the shower.
I sing when I'm driving.
I sing along and harmonize when I'm listening to music.
I've never actually sung on a cake, but
I sing very loudly and with faked accents when I think no one is around to listen.
I've sung lullabies in French, German, "Irish" and British English.
I like musical movies because I can sing along.
I've sung in a mall to coerse my son to hold my hand.
I sing when someone says something that reminds me of a song.
Sometimes, when the kids were little, we'd have "Mr. Rogers Operetta Day" and sing everything we wanted to say.
I obviously have too much time on my hands at this particular moment in time...
I'll go sing while I clear up the kitchen and bake a banana cake for supper.