It depends on a lot of things.

• have you spent an entire day or even better a weekend together?
• are you ok with the loss of independence, alone time can be much more difficult after moving in.
• do you have room for their stuff?
• are you ok with rearranging your place, and potentially losing certain decorations or room functions?
• are you comfortable talking about how finances will be managed?
• do you have compatible diets and eating habits?