He's been on his phone all night
As soon as my bf (who claims to be polyamorous and wants me looped in on the lifestyle too-- blech) got home from work last night, he went straight to texting someone else. The entire night. Until midnight. I'm fairly confident it was another girl. This "poly" bs does not mean that I would be okay with that. Not only that, but I just find it rude as hell for him to be giving anyone else on his phone more attention than me.
In my opinion, if you love somebody you don't want to share him/her. I cannot imagine that I am together with a boy who is interested in another girl too. You have to make a decision whether you accept this lifestyle or look for another man. Even if he is really polyamourous, it doesn't mean you have to agree with his views. At this point, I think you should start to think about your own sake.
Hope you will find your own way.
You sound like you have never bought into this poly lifestyle anyway - now you see why it doesn’t work for you at all.
Therefore, he’s cheating on you.
Let him know how you feel and make a decision from there.
If you are bothered by it now, then you will probably always be bothered by it. Your happiness is important.
If you say that he’s polyamorous that meant you know that you are not the only one. I think you should make your decision from the beginning and if you can deal with it you’re not bothered with him texting other girl. If you want to clear things up maybe you should ask him and make your decision from your heart and if the result is he’s committing with another girl too i think you should find your happiness and find another man