Hi there cheungown, sorry hadn't noticed your post so apologies for the slow response. There seems to be so many snags and hitches no matter what you choose, it's no wonder people get confused.
No, I wouldn't want my DP to struggle financially. I think we would have to review our Wills at regular intervals to ensure everything is up to date and appropriate for the relationship.
At the moment, we are buying a house together, having sold both our separate houses. DP had a huge mortgage on his house and very little equity and he had no savings. Mine was mortgage free, plus I have some savings, so I am putting in 75% of the cost of buying our new home. The rest will be provided by a mortgage in his name, though if he defaults on it, I will have to take it on.
If I had died at, say Xmas, my DCs would have inherited my current property. I am hoping that we will be able to reduce the new mortgage as quickly as possible so that the property becomes mortgage free and my DP's 25% will enable him to buy something much smaller but equivalent in size to his previous home. It may be that I'll change my Will so that DP and DCs get equal shares, but they would need to sell the house to receive their inheritance. If DP dies before me, I would hope to have the means to buy out his 25%, but I'm assuming both of us will be alive for another 10 years (we are late 40s/early 50s)!
DP and I are not married and have been together around 18 months. I expect/hope we will grow old together but who knows what could be lurking round the corner - I need to protect myself, my DCs and DP from being worse off than we were before, should we split up for instance.
Unfortunately I have limited knowledge of correctly wording Wills and that is where I'm struggling.