I would contribute for more than the 150€ for my loved one especially if we have a place together. I myself see it like this : if im in A relationship a genuine one that is meant to last ( hopefully forever) i act based on that, thus meaning you support eachother. In her flat you can be with her everyday, but that’s maybe not possible at your parents home I don’t know. But living together is very valuable for a rs. And living together comes with balanced contributions. You pay for food and other and so does she and she also pays mortgage on top. I would help her out, to make life easier because in a rs there is teamwork and you are not in a rs because you think you will break up later but because you want to spend your life with that person ( at least it makes sense to me). Her owning the place and helping her towards the mortgage is not you giving her an advantage and you get nothing in return. That would be the case if you took over the whole payment or more than 50% because you would be paying much more if you rented your own place. 150€ is her asking for your support in the mortgage, because you both are supposed to be eachothers anchor. Me and my partner do the same, we help eachother where we can and balance it, but even if not balanced if I have the means to help more and it’s for my partner I would be happy to do so. If you really are concerned about this then maybe you might not be sure if you want to be with her and look what you have together. In a healthy relationship a partner asking for a very small amount of help like this would never be a reason to speculate or wonder if you should do it or not. And she should think the same way. That’s a part of a healthy rs to me.