Send her a friendly and non - pushy message like 'I noticed you've been watching my stories. I hope you're having a great day!' This shows that you're aware of her viewing but also keeps it light.
Give her some space. If she's interested, she may eventually start replying. Meanwhile, focus on other aspects of your life and your other friends too. Don't let her lack of reply make you overly obsessed. It could be that she needs time to figure out how she feels about you or how she wants to interact with you.
Perhaps she doesn't know what to say in response. Watching your stories is her way of staying updated on your life without having to come up with a reply. It could also be that she doesn't want to engage in a conversation directly but still wants to be part of your world through your stories.
Maybe he's shy. He might be interested in you but doesn't know how to start a conversation. Just watching your stories is his way of staying updated on your life without having to interact directly yet.
I don't think you should be overly concerned. Everyone has different ways of interacting on social media. Some people are more passive. He might be one of those. He could be enjoying your stories at his own pace without feeling the pressure to reply immediately. If it really bothers you, you could try sending him a friendly and non - pushy message to see if he'll start a conversation.
She could start by having an open and honest conversation with him. Let him know how she feels about it.
If you're curious about 'ghoster', you might try to drop some hints in your next stories to see if they'll interact more. For instance, you could ask a question related to your story content and see if they respond. But don't push too hard, as they might be someone who prefers to stay in the background.
You could react by simply ignoring it if you don't want to encourage any further interaction.
Maybe you can try sending him a friendly message related to one of your stories. For example, if it's about a new place you visited, you can say something like 'I thought you might like this place too'. This way, you're not being pushy but still opening the door for communication.
Another option is to send her a private message, but keep it casual. For instance, you could say something like 'Hey, noticed you checked out my story. How have you been?' This way, you're opening the door for communication without putting too much pressure on her.
You could just ignore it. If he rejected you, there's no need to give his actions too much thought. Keep living your life and focus on yourself.
If it makes you uncomfortable, you can block them from seeing your stories. It's your social media and you have the right to control who views your content.