Dogs are very emotional creatures.
Sounds like he has separation anxiety....my daughter's dog does the very same thing....he mopes, if he's not glued to her.....he comes to life, when she walks in the room....he's in love with her....and your pooch is in love with you.
It is pure love.w/o conditions. Animals are truer many times than ppl.
I think he loves you very much and since he can't tell you, he'll show you one way or another! I agree they are emotional creatures, but so is the human race.............
watch out, he is in love with you. Did you ever see how Brian was in that episode of Family Guy?
is he in pain?