The surest way to drive a man off is by being overly needy, clingy and pushy. The fact that he has already given you the keys to his place inficates an enormous level of TRUST. Are you unaware of how significant that is?
To me that would mean a lot more than just words. And what precisely is this next level?
Is it just calling each other boyfriend and girlfriend? Is it living together? What exactly is it and why are you being this impatient about things.
Three months is nothing. Is this the man you feel you’d want to be married to and spend a lifetime together? If so, a mere three months is a drop in the ocean.
He sounds quite a bit more mature than most guys who will say what they think a woman wants to hear just to get into her pants.
This guy sounds like he actually cares about you too much to hurt you with empty promises. You should be glad for that.
And the plain fact remains that if he decides that you are not the one and only for him, there isn’t a whole lot you can do about it regardless of what you manage to arm twist him into saying. That’s the plain truth.
The more you pressure him, the likelier you make it that you will drive him away eventually. You will have created the exact thing which you fear.
Relax and allow the relationship develop naturally at it’s own pace, use precautions against unwanted pregnancy and enjoy what you have.
Make yourself someone he feels joyful about spending time with not someone he needs to avoid feeling pressured by. If it’s meant to be longterm, it will be.