Just to answer a few questions, he is 3 years old I got him when he was 3 months old, he has been castrated for a couple of years now but still humps one of his toys now and then, no ones ever hurt him, we did take him to training classes a couple of years ago didn't go too well not good with other dogs we went for about 6 months and had to stop as he was getting worse and disturbing the class.
He has always had a good bond with my dad that is why I left him with my dad while I was away for 5 weeks.
He's totally not spoiled does not go on sofas and is treated as I would treat any dog.
I spend the majority of time with him on a daly basis so I think he thinks I am his, I'm trying to distance myself from him and my partner and myself are sitting on one of the sofas together.
Thankyou for your comments, I will think about the vets for a check, but that is a real challenge since he was microchipped at 4 months i.e he hates the vet and has to wear a muzzle.

He is resource guarding you.

Get this book, which will demonstrate how you can deal with this in a kind way.

http://www.amazon.co.uk/Mine-Practic.../dp/0970562942