After reading this thread and OP's other one I sense she ran away from problems back in Michigan, which appear to be to protect her son, but the divorce isn't final and there seems to be more back story there and why she won't move back. I know many couples that divorce and still live in same town. OP mentioned cheating and lies but nothing of physical or mental abuse (lying/cheating abuse yes).
Now OP is in an unhealthy poly fidelity relationship where she really hasn't explained the true details of the relationship. I can't tell if its a triad or V only she lives with them, does not trust the wife (cell phone looking etc), the girlfriend/ wife doesn't want OP snooping through her phone, OP thinks she's hiding something because husband/boyfriend allows OP to go through his, wife/gf is envious of OP and husband/ bf getting more time (appears to be a quantity issue versus quality issue for the wife/gf and with all these facts I'm still confused on the true relationship between these 3 individuals.
OP I really think you providing us with exactly the true relationships between the three of you can help us to provide the true answers you seek.
1-you are emotionally and sexually involved with the husband, yes or no?
2-you are only emotionally involved with the wife, yes or no?
3-did you legally take your son out of state?
4-was the relationship with soon to be ex physically abusive, emotionally abusive or you left because he cheated and lied?
5-in your own words what does polyamory mean to you?
Providing all of us a clearer picture of your situation allows those who are willing to advise a better idea of what to say.