Can you ask a Sim to move in with yours when they're in a relationship?

Question

I'm currently playing as a family of one Sim and a cat. The Sim got romantically involved with another, and I wanted to try and ask the other Sim to move in with the household. The problem is, from what I can gather this is a Friendly related option when talking. But this option does not appear for me in the talk options. I have seen it once when I was building the relationship between the Sims, but now I cannot find it anymore.

The Friendly talk options contain all sorts of stuff for me. My Sim has a lot of extra options in the Friendly screen (she's a Witch with various traits that give quite a few extra talk options in this screen). Note that their relationship is at the highest level: the bar is fully green.

So is it possible to ask that Sim to join the household, preferably without breaking up? Or is at this point marriage the only way to do this?

Answer 1

In the Sims 3 sims have a hidden 'instantaneous relationship', that is taken into account to determine what options show in the pie menu.

This means that in order for 'Ask to Move In' to show up (it shows up under Friendly), you need a number of things:

1. A reasonable long-term relationship. It doesn't need to be very high, aim for at least 30 or 40.
2. High instantaneous relationship. This is done by stacking friendly talk options and building a conversation.

Once you have both of these, 'Ask to Move In' should appear under friendly, and when selected, is usually accepted.

(The same basic flow is used to make available stuff like proposals and propositions generally.)