Dogs don't necessarily show jealousy or envy, but definitely have wants, Terri Bright, director of behavior services at MSPCA/Angell Animal Medical Center, tells The Dodo.
"If someone has something dogs want and is giving it to someone else, they will try and get it," she says.
And if the dog has been given what he wants in the past, that behavior has been reinforced, and will likely occur in the future, she explains.
"So though you could say, 'The dog is jealous and gets in between me and my boyfriend whenever we are trying to sit together,' it is quite likely that the squirming-into-the-middle-position has been reinforced in the past," she says.
"I would not attribute anything devious when a dog tries to get what he wants," Bright added. "They are fairly simple food and attention-seeking creatures."
So while we may think a dog's behavior is implying jealousy, they may just be telling us what they want. And dogs certainly want what they want. Don't we all, dogs. Don't we all.