to Jewishishfeminist02 who wrote “You’re describing older singles who have roommates/suitemates. Nothing wrong with that, but I’ve never heard of an arrangement in which they share assets.”
Its quite common for long term roommates (housemates, whatever) to end uphaving joint accounts, shared assets, often buying a house or car together. When the relationship ends (voluntarily or through death), it can create great complications (and of course, great opportunties for parnassah for lawyers).
And it has nothing to do with gender or sex.