Can a divorced couple remarry?

Yes, sims can remarry as often as they want. If you don't want to use MC, you will have to go the normal route: romantic interest (woohoo doesn't trigger that btw), going steady, propose, marry. You can do that within a single conversation. Make sure you get them to "extremely irresistible" through the usual romantic interactions, or none of those options will show up.

It may be good to tell the other woman to "just be friends" though, if you don't want any further surprises.

Their relationship is completely maxed out green, Tom sent enough insulting texts to his romantic interest to kill the relationship, and he is being extremely irresistible yet no options for engagement or marriage with Rita. I guess I'll let them sleep on it a night and see if anything changes. I hate to use "cheats" to get them back together if I don't have to.

Sometimes, simply quitting and reloading the game helps to get missing options back. Also, the first option you should look for is "go steady".

Has Rita asked him to be her boyfriend? Propose and marry wont show up until you have done this step.

Yes, your Sims can be remarried. No, he doesn't have to break up with his romantic interest for that to happen but it would be better for his marriage if he did. Breaking up face to face is better than text (if you can manage it).

How does Rita appear in his relationship bar? Does she have the empty heart with the red 'x' on it? If so, have them do basic interactions until the option 'Ask to Be Friends' appears. This will remove the 'ex' symbol and give them a 'clean slate' (so-to speak).

From there, have them spend time together doing all the interactions and things they like to do together (whatever that is). Rita will eventually forgive him and they will move forwards and towards marriage again.

Does Rita still have negative moodlet due to Tom cheating? it could be the only obstacle preventing them to get together again, try waiting for the moodlet to expire. it usually last around 5 in game days.

Rita has the wedding ring moodlet with an red X on it and hovering over it says "ex-husband". Same with Tom. There are no options to be boy/girlfriend or go steady. I went into their memories and deleted references to the cheating and the divorce. Both relationship bars for each of them is all the way green. I have closed and reloaded the game and it's still the same. The only suggestion from here I haven't tried is checking to see if there is an option to ask to be friends. I've been focusing on the romance interactions. I'll try that when Tom gets home and see if it gets them further along to reconciliation.

ETA: No go. There are no "ask to be friends" interactions and still no proposal or marriage option. I'm tempted to move Tom out, and have Rita invite him over and see if it can progress from there.

The 'Ask to Be Friends' comes up in either the 'Friendly' or 'Mean' category (and I think it is under 'Mean' for some reason). Personally, I wouldn't move Tom out because he then becomes a townie and will have free reign to pursue (or marry) whomever he wants (or the game wants to puts him with). I suggest keeping him under your control until the block which keeps him and Rita apart can be removed. Just my opinion.

: ) I'm sorry this is late Rhiannon58 hopefully it got solved, but if not I have luck with what mw1525 said to do:

First have them do a few Friendly category thing (not romantic),
Then go to the Mean category and 'ask to be just friends' will be there.
Only then will the wedding ring with the red X in it disappear.
Once that happens, you can start with the romantic things to get to Propose.

Hi!! Yes, of course, your sims can remarry if they want to.