It sure if you're still reading or not, but in case you are...
6 months isn't very long, especially in these odd times, HOWEVER, you are supposedly thinking 'long term' & are supposedly 'a team'. & he's not acting in line with either of those things.
I'd totally support him buying something in his name (you have a house in yours) but, to me, if he GENUINELY thinks of you as a Team & is thinking of this being long term he'd be discussing it with you & you'd be deciding together what would be the best option. Buying near his parents, rather than where you're planning on setting up home together sounds like one foot in/one foot out to me. (At 6 months, that's fine, but he's not being honest about it)
You earn 3x what he does, be careful you don't end up subbing him - housing costs, meals out, entertainment, clothes etc. It's very easy to do when you love someone & you earn more- but it's easy to feel you're subbing them buying a separate property later on.
Would you both not consider buying a house together? Rent yours out, then buy one equally for you both to live in?