My game is patched up to 1.24 and I have every expansion and stuff pack up to Town Life.

Recently, the last few of my sims I've married off have not automatically moved in together. Furthermore, the sim I'm currently playing has already been married once without moving in with her husband. That husband is now deceased and I would like to marry my sim off again. However, when I tried to do so just now, the game insists that married sims must live together. I tried restarting the game and got the same result. I really don't want to add this guy to my sim's household but I don't know what to do. I hope I've explained this clearly enough. Any help would be appreciated.

Living with one's spouse is highly overrated. Just ask the 50% of couples that got divorced.

try moving him in, getting them married and then moving him out again.

Normally moving him in and then kicking him out would be an option, but I've got this whole black widow storyline going. Part of it involves my sim getting her rich husband's money after she kills him (I've got Twallan's Assassin mod and his story progression so she gets an inheritance) and if he moves in she only gets 20,000. I know there are other ways to transfer his money to her manually before they get married, but it's just not as much fun. At any rate I've managed to do this before with this sim and others from different saves. I'd really like to know why I can't seem to do it now. I even tried having her marry an entirely different sim and the game still insisted that married sims have to live together. My storyline aside, I'd like to figure this out so that I can avoid this problem in the future.

twallan's SP, if I remember correctly, will attempt to move married Sims in together. Perhaps that has something to do with it. Have you been using the mod all along?

Yes I have.

Can you take the mod out then and see if it still happens without ruining your plan? It could be the mod but hard to say since you are on an older patch level (why is that?) and I honestly dunno if he has changed something between then and now in regard to the moving in upon marriage scenario. Possible there is a criteria that applies to this marriage that somehow didn't apply to the others???

You may also want to post on twallan's wiki to see if anyone would know anything or have further suggestions since you are using 2 of his mods.