This man is not up on his poly. I suggest he come here and do some reading. Red flags for me are his OPP ("One Penis Policy"... you can check the tags in the search engine and see what others have written on that) and that he wants you both to be sexual with one another for his own benefit.
First of all IT IS hypocritical to ask that you don't see others. He has no right to control your lives that way. If he can have two partners, you can. Full stop. End of story... If he doesn't like it then I suggest he not have more than one partner himself.
It is completely unreasonable that he ask the two of you to sleep in the same bed with him and have sex. Sure he can fantasize about it all he wants and that is fine, but you have no obligation to do so and it is not mandatory. You can do what is right for you and I suggest you do.
Have you met this woman? Spent time with her? Have you gone about establishing a metamour relationship with her of some kind of respect and understanding? I suggest doing so if you haven't already. Knowing and being at the very least able to approach ones metamour quite often eases any jealousy or stories that go on in ones head. It is so easy to make assumptions about people when you haven't met them and don't know them.
Yes it is possible to have a vee that is successful. I suggest you do some reading here and check out some tags that interest you. There are many accounts of peoples stories that you and he could benefit from.
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