Throwaway account:

My partner and I (41f) (40f) have been together for over 8 years. We have mainly participated in an open dynamic without emotional attachments and that was 2xs. They have met someone and have been pursuing them for about 2 months. My partner and I are going through major life transitions and in the beginning I had asked them if they would wait to develop this relationship with this person until we can get our home life more stable. They have chosen to pursue this relationship in tandem with trying to fix things that are going on with our relationship. They said they are going to emotionally invest in both relationships because they feel like they don't want to lose this other person. I can see where they are coming from but to me everything feels rushed and their is a sense of urgency for my partner because they will be gone for a few months because of work and won't be able to dedicate much time to this new relationship or even ours. I am worried that the way that they are handling this connection with this new person is not necessarily healthy for us. I know vetoing is not what should happen and I am not going to do that but everything feels haphazard. Especially, because we have not even done the work as a couple or individuals to have more polyamorous relationships with deep emotional connections. I feel stuck because I am afraid that this will cause a lot of emotional damage for me in the long run and I am not even sure how to go about all this. I need some type of advice but I don't even know what the exact advice is that I am looking for. I just hope someone can say something that will click with my brain.