Since this is something EA is trying to fix, I think it's an appropriate spot to use a cheat to get around the issue.
There is a cheat to modify relationships, and you can use it to lower the level enough to no longer be best friends, and then raise it back to where it was. You will then be good friends but just as close as before. You will also be free to ask another sim to be best friends. First, cheats have to be on with testingcheats true. Then, use
modifyrelationship YourSimFirst YourSimLast TargetSimFirst TargetSimLast (-)amount Track_type
where amount is a number from 0 to 100, and Track_type is either Friendship_Main or Romance_Main
I used 80 for the amount and it worked. Entering the cheat in the command line, with your sim being Keith Pots, would look like this:
modifyrelationship Keith Pots Bella Goth -80 Friendship_Main
Hit enter, and you should get a notification that the two are no longer best friends. Then go back to the command line and enter
modifyrelationship Keith Pots Bella Goth 80 Friendship_Main
After that, you should get notification that Keith and Bella are good friends. I used this to get around the bff issue in the soulmate aspiration, but in another file I had problems using it with J Huntington III. I think it was because of the three names, but there may be a way around that with brackets or quotation marks. I didn't experiment and just insulted him until no longer friends, then apologized and used a lot of friendly interactions.
Jess
