Re: changing relationships

You can do so by using cheats or mods. Here is an example of a cheat that changes relation ship to married:

Press CTRL-SHIFT-C to open the console.
You will need these commands:
testingcheats true
Sims.get_sim_id_by_name {firstname} {lastname} for both Sims. Only the numerical part is needed.
relationship.add_bit {FirstsimID} {targetsimID} family_husband_wife