This is an experimental roleplay.
Your children are waiting to surprise you and your spouse for your anniversary, but when the two of you got home, your children realize you're in the middle of a very heated argument that shocks them; they never heard you and your spouse yell and say a bunch of swear words at each other this way. So instead of jumping out their hiding spots, they stayed there and watched silently.
You were too engrossed on this argument to notice the house is eerily quiet, but you know they're there. Remember whatever happens tonight may affect the family dynamic; this argument may scar the kids for life, or this will end up better than expected. It's all on you and your spouse. Act like responsible adults to make a good example...or not.
You can brainstorm what kind of argument you're having. You can also name the children and your spouse if you'd like.