Hi, My Partners 2 Year Old Has Started Getting Bad

Hi, my partners 2 year old has started getting bad separation issues. I work all day and she is at home with him and recently he wont leave her alone he follows her to the bathroom and wants to sit on her all day. I get home and make 1/2hour play time and soon as i mention play with toys he breaks down crying and chucks a tantrum. He will stand in the room watching down the hallway and wont play with his toys. Same if we are in the backyard he hates being more than a metre or two away.