A group of people, who have known each other for a very long time, meets again. Among them are Alice and Mallory (not real names).
She has been gone for quite a while and just came back. Now she has a lot of new stories to tell, and we are eager to listen to her.
She is an attention-seeker and dislikes Alice. Furthermore, she is very sensitive.
Now, everyone is present and Alice starts to tell us about her experiences during her time away. The rest of us met more regularly, living in the same city, so there is currently no news to share.
Mallory doesn't appear to be too interested, judging from body language (she sits close to me, in my line of sight). I am however, and listen to Alice. After a short while, Mallory simply starts talking to me (directly, and just to me). She speaks in a loud voice, telling me the same old stories she already told me a thousand times, laughing and also grabbing my attention by physical means (poking, pushing). All this, while Alice is still speaking and I'm obviously listening to her. The others ignore what is going on, Alice included. Since Mallory is so sensitive, she is rarely criticised for her behaviour, in order to avoid her throwing a temper tantrum.
I want Mallory to stop, without interrupting Alice. So I'm looking for a discreet way of making it clear to someone, that you want them to stop talking to you. So making a scene is not a possibility.
How do I handle this situation without grabbing the attention myself?
We are talking about adults here (including Mallory).
Regarding Mallory's motivation: There is no special interest in me (especially no romantic one) and she did/does that on several other occasions involving other people.
Removing / not inviting Mallory or hoping for her to just stay away, if she is not interested, is not an option. There is no possibility to physically get rid of Mallory (e. g. leaving together with Alice).
Mallory is an extreme case for sure, however I also welcome answers, that are more broad in their approach - how to handle someone, who tries to drive your attention away from someone else for no good reason. And it is about the situation itself, not about what to say to Mallory afterwards to make her stop that behaviour in the future.