That's fine Snape, it would be a pleasure to help 
I would say he informed you he met someone via text because he couldn't face telling you in person. If you didn't mean something to him, he would have just told you, he wouldn't have given a toss.
I know you know it's not emotionally healthy for you because we have discussed it before. All that worries me is you getting hurt. Him meeting someone and dropping you like a hot cake. I would hate for that to happen. I know it's all nice at the moment, it's bloody lovely and makes me smile every time you post, but you want more, and you are not going to know if he wants more, or if there is even a possibility of it becoming more than platonic unless you talk about it. But you already know that 
Maybe it is tedious mixed signals, but maybe it isn't. I do wonder if you idolise PM and have him on a bit of a pedestal. If you are thinking he won't possibly be interested in you then you will be reading the signals all wrong. You might be missing what is staring you in the face. Laying on a sofa with your feet on a womans lap, while she rubs your legs, well that's a bit more than just friends, that's intimate, and he didn't object. And why is he trying to get you to sign up to Cupid? I can't help but wonder, especially now you have told us he is a romantic and a feminist, that he is waiting for you to bring up the subject. Maybe he too is scared of rejection, maybe he is thinking exactly the same way as you. But we won't find out until you talk to him.
If your list pays off and the Universe delivers, how will you feel? Will you be able to walk away without a backward glance? Will you feel ok about telling PM to his face that you have met someone? Could you live without him in your life?
You two have something special, there is no doubt about that. He is a big part of your life, your family, you are already in a relationship, you are two people ignoring the obvious because thinking about it, thinking about the changes it might bring, the losses, well, it's just too scary to face.