6 months- moving in together?

So me(22) and my SO(24) have been together for 6 months now and my current tenancy runs out in August. We're pretty certain at this point that we will move in together when this is up as I have got a job in this area and he wants to move out of his parents. The conversation initially came up as it makes more financial sense for us to move in together and split bills/rent etc but continued conversation has made us what to regardless of that. I've made it clear I want to do this for the right reasons and not just because it makes sense money wise.

Then he drops the bombshell that his parents are willing to give him the deposit money for us/him to buy a place! Obviously I understand that it would be on his name etc as I cannot stump up the money to contribute to a deposit and my family are not in the same position to be able to help. I've stipulated that I thing it's still a good idea to still rent together first make sure it's 100% before we go any further.

Am I being too cautious, anyone got success stories they want to share? My parents have been married for 24 years now and they were married and moved in together away from home in less than a year with a significant age gap and it's worked for them (my mum was 19 and my dad 30!)