There is no reason that she needs to quit him I don't think... I think what does need to happen is meeting him, getting to know him, discussing boundaries and time lines so that she can spend time with both of you and it be special and your time only (no texts). The other big thing is to slow down. If her seeing him so much is too much, then ask that she see him less right now. Poly, and all relationships are about expressing needs and making requests so that we can process and go at a pace that is comfortable... not about doing whatever and then just expecting and assuming the others in the dynamic are sucking it up as much as we are. Communicate, respect each other, empathize, spend time getting to know each other and make sure that you are doing right by you first... while keeping others in mind...
Take a look at the tags, do a search in them, look at the stickies and golden nuggets section and educate yourself... then you can make choices that are rational and educate others so as to benefit you and them... I suggest that the two others in this do the same. Good luck.
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