I just posted on another thread which suspiciously sounds the same as this but from the blokes pov
Don't know how to link but it's in relationships with 'My girlfriend is pressuring me to move in...
Anyway, yay, as others have said, he doesn't sound that into you.
Maybe he thinks you're not 'The One'. Of course he's happy to see you and have the 'perks' of having a gf as long as it doesn't change up a gear.
You have to ask yourself and him, after 2 years ( which is long enough to know whether you are compatible etc IMO), why he says he doesn't feel the relationship is strong enough.
TBH I wouldn't waste my time. You need to get on with your life and find someone who has no second thoughts about wanting you in their life.
FWIW, my now DH, when we'd only been dating 4 months, gave me keys to his place totally unprompted. He was in his 40s and me in my 30s, and I had my own flat (so no need to move in iyswim).
I'm all for giving things a fair go, but I think here you should move on and let him go.
Sorry for your situation, but I don't think he'll ever commit to you. 