Since the statement is not very clear, you could start by having an open conversation with your daughter. Try to find out if these'stories' are making her sad or if they are having any negative impact on her mental state. If they are, you might want to limit her exposure to such content in the future and provide her with more positive and uplifting things to engage with.
First, you need to clarify what 'go black stories' means. If it's about her being exposed to negative or disturbing stories, you should talk to her. Ask her how she feels about what she has seen or heard.
This statement is rather unclear. 'Go black stories' isn't a common phrase. It could potentially be a very creative or misphrased way of saying she was involved in some dark or sad stories. Maybe she was exposed to some difficult or tragic tales, but without more context it's hard to be certain.
You could just ignore it. If you don't want to engage with your ex, then act like it didn't happen.
You could simply like one of his recent stories if you want to show some reciprocal attention.
First, you should try to stay calm. If it was an unjust spanking, you can talk to a trusted adult about it later, like a teacher or a parent. But at the moment, getting overly emotional might make the situation worse.
You should firmly and politely tell her that it's not acceptable. Explain the importance of respecting social norms and the feelings of others.
You could just ignore it for now. Maybe he'll come around later and text you back. Don't seem too eager or pushy.
You could wait a while and then send another non - pushy text, like something funny or just a simple 'Hope you're having a great day'.
It depends on how you feel about your ex. If you have completely moved on and are indifferent, then there's no need to do anything special. But if seeing their name among the viewers makes you feel a bit of something - whether it's annoyance or a twinge of old feelings - then you need to assess what you want. If you want to cut all ties, be firm and block them from seeing your stories. If you're not sure, maybe limit what you post for a while until you figure out your emotions.
You could just wait and see if they eventually reply. Don't overthink it too much at first.
You could also try to get involved in these interactions. Join in when they are sharing stories and see what it's all about. This way, you can better understand the dynamic and your wife's intentions. If it's all about positive cultural exchange and friendship, there's no need to overreact.