I really don't think this is the intended functionality, if it is then it's bad design especially considering that it breaks other functions of the game. It doesn't seem logical to me that it was intentional for that interaction to make 2 aspirations impossible, make at least 2 whims impossible (both the generic and specific whims for asking someone to go steady), and remove the ask to be boyfriend/girlfriend interaction.
The description on that promise is very vague and generic anyway, "These Sims have promised that they will remain a couple forever", which if it's simply about being a couple then isn't being boyfriend/girlfriend considered being a couple? I feel the intended functionality was for you to stay boyfriend/girlfriend if you already were, and to allow you to become boyfriend/girlfriend if you weren't already. Or if it is going to remove boyfriend/girlfriend status, at least still give you the interaction to become boyfriend/girlfriend again and have it remove the "promised" status.
At least there are workarounds, because it seems not enough people even know about this issue (or maybe don't care lol) for it to ever be fixed. This doesn't seem like something we need workarounds for though, seems like something that should just have better functionality. I at least know not to use that interaction ever again. It does nothing positive (only adds that "Promised" status in the Sim Profile) and breaks other functions, so it's essentially worthless.
