<human>: Throwaway here, since the boyfriend is also a redditor.

My boyfriend and I have been dating for 3 years, and living together in the house that he owns for the past 1 1/2. To contribute, I pay him a monthly "rent" to help out with his mortgage and other bills. It's a very low amount compared to what most people in my area pay in living expenses, so as a result, I've saved up a fair bit of money. Assuming all continues to go well, we plan to purchase a house together in the next couple years, as the one we're living in currently is a "starter" house in a not-so-great neighbourhood, and we can both easily afford a better place. 

My problem is that although my partner makes a bit more money than me, I will almost certainly be able to pay a far higher amount as a down payment on a house due to all the saving I've been doing while living with him. I'm happy to do this, as I'd like to keep our mortgage payments as affordable as possible, however my concern is that if our relationship turned sour shortly after purchasing the house and we split up, would I have any hope in getting my higher percentage contributed to the house back? Is there any way that I can protect myself in the event that this should happen, or should I just insist on us contributing equally to the home and suck up the higher mortgage payments? If you've been in a similar situation or have any input, please share!

Could you distill the essence of the text into 1-3 sentences?
<bot>: Boyfriend and I will be purchasing a house. In the event of a break-up, can I be sure that my greater investment in it would be credited to me?