In sense of
speech.
One who talks soupy is being mildly flirtatious,
almost drool falling off their words, but trying to hide it.
Boy: “Yeah I just got a dog. I’ll show you.”
Girl: “AWWWWWW!! I love
dogs too. Blah blah blah blah blah blah blah. Yeah
dogs! We’re so alike. Do you want my number?”
Boy to his
friend: “Damn she acts soupy...”