How do you know if a Jellyfish loves you? Does it hold the door for you? Does it bring you chocolates? Does it send you little notes saying "Do you like me, circle Y or N?"
Probably not, because higher cognition is not a Jellyfish's forte. It's made out of jelly. Jelly + fish = Jellyfish. Floating without destination, gently pulsing in the the mellow azure currents...sounds pleasant!
So perhaps he'll show his love by bumping into you repeatedly, or nuzzling your nose with his front. I mean his back. I mean his side. How can you tell? A Squishable Jellyfish is built for hugs, not directional navigation!