As long as you can get them to clean up their own messes (which would be a feat in itself) and put the toi-toi seat down, it's ok.

And as someone who is now divorced and an only child, I found out I resented him moving into MY space. It was a mistake but financially speaking, since I own my condo, really our only option at the time. Deep down I hated it tho. A couple should really get their own first space together, for sure. (If possible.)

Unless he owns a mansion and you move in and have your own rooms and pools and servents. Pfft, ha!

I've lived with my boyfriend for 19 years. We have our own rooms, our own beds, and that's how I like it. You may think it's unromantic, but I'm getting the feeling you're quite young, and being in a relationship isn't all lovey-dovey all the time. Everyone needs their own space sometimes, and your partner can sometimes do things that get on your nerves, and vice-versa. That's not to say there's no real romance, but it's not constant and always sweet, the way I think you're picturing it.