There are some dogs who can smell cancer, or low blood sugar in their humans, so don't underestimate the intuitive powers of the dog
How old is the pup? I've read that during puppyhood they can go through clingy phases (along with all the other myriad phases dogs go through in their first 1-2 years of life). If it's bothering you, the only thing I can think to do is start training Marley to have a "place," like a mat or a dog bed, and to go there on command and stay. It would take
time but you could get a little space that way. If you want it!