Please use this thread going forward: Newlyweds can't cut first slice of wedding cake | EA Forums - 12056155
Weddings are broken as hell...I just gave up to ceremonies and marry my sims without it, only "law" or "administrative" (IDK is there an analogue in English, when a couple just register their marriage on documents)
I've had this issue as well. I find that the game doesn't recognize the sims who just got married as "Newlyweds" for whatever reason, so they can't cut the cake.
I did find a fix for this, though. If you have testing cheats on, shift-click on one of the newlyweds and click "Marriage" then "Marry [Sim Name]". For some reason, the game will now consider them married and you can cut the cake. I'm not sure why it doesn't consider them married the first time, but second time's the charm, I guess...
Edit: just noticed that somebody literally gave the same instructions a few posts before me so I apologies for re-stating the same work-around! My bad!
Thank you for the work-around.
Sad that you have to invoke a cheat to get through the event though ☹️
I noticed some group activities are broken after patch as well: the bowling lane, the juice-pong table, the wedding carpet and also you can't invite to stay-over more than 2 sims (and you can not assign them double beds anymore despite the invited sims are spouses). I am sure it is not mod related, tested on another machine without mods. The issue appears only after update, reverting to pre-patch game version helps, hence this is in-game issue, dont even check your mods. Sending those bugs to reports means do nothing, you will crack the code, learn the Python and xml and fix this manually a way faster than the "developers" get tired counting money and do something related to their job directly...even Russian modders do better with swear and hammer than an entire overpayed crew
