Don't do this.
Keep that money safe.
YES - rent for a year, preferably two. The housing market is all over the place now anyway, prices might go down. You're certainly not necessarily losing out financially by not buying now.
He's not necessarily a bell-end, but he sounds like one, alas. Let's check it out, eh, in the interests of well-thought-out forward planning of your future. The most important thing you can do in this respect is make DAMN SURE that the guy you've chosen isn't a steaming wanker underneath it all. 2.5 years isn't long enough, I'd say. Not when there are a few red flags popping up. You sound sensible. Live together for another year or so, renting - keep your eyes open, keep your cool, and make it clear that you aren't going to be sutmping up 25K anytime soon with someone who:
a. Seems to think that he can decide when/how/if YOU talk about certain subjects. He doesn't get to 'allow' you to talk about anything, and more to the point he needs it made very, very clear that he will not be dictating the pace of your relationship. You both will. Jointly. By talking about stuff.
b. Has a nasty little habit of sidelining you 'When I have kids'? 'Yes I'm moving out and getting my own place'? Hmmmm. Don't like that. At all.
c. Is 31 but clearly has issues about talking about the future full stop, and whose default position was to move back in with his parents after a break-up rather than get his own place, despite being in a good job. Why?
I don't like the sound of him at all, OP. I read it as him being delighted to be handed a 25K deposit on a plate, rather than delighted at starting your joint life together. Call a halt to the house buying, insist on a year's rental contract, and see if after a year you're a happy bunny, or feeling sidelined, talked down to and pushed into second place by a fairly selfish, childish man.