I'm going to try to be completely honest and impartial here. Looking for advice on WWYD if this were your dog.
Gorgeous 7 year old dog we've had seen a pup.
Hes ALWAYS had problems with being possessive. Up until about age 3/4 I genuinely thought he would need to be put down let alone given away. He's lovely 90% of the time but if you do something he doesn't like - like take something he shouldn't have off him - he'll have hackles up, snarling, and on one or two occasions has air snapped.
He's now almost 8yrs old and has chilled out lots - mainly because we've learnt how to manage him. I know what to do and how to handle his triggers. This means we are generally living with a happy dog without incident.
This weekend he went for another dog (he's normally great with other dogs but hates flat faced breeds) I went to pull him away and he spun round and air snapped at me whilst growling.
The same evening I left the kids (4&5) with my mum whilst we went for a rare night out. The kids tried to push him off the sofa (a trigger that I would always immediately stop if I were there). Hackles up, showing teeth and growling at them 
He's always been brilliant with the kids. Never shown any aggression with them at all until now.
I love him so much but WWYD?