You have a short term problem -- this "oopsie" thing. It was just today/last night? If the goal is to be not pregnant
-- are we not talking about her taking ECP
to prevent implant? You are still in the window. You don't have the time to "take it one day at a time" with preventing pregnancy.
G is being careless in not wearing a condom and so is she -- allowing sex without protection with all these kids and crowded living conditions.
Deal with that first.
Then you have what appears to be the longer term problem.
He says I'm always like this, that its always something.
There seems to be a lack of boundary keeping here and accountability.
Rather than making it be about your feelings -- how about making it be about behavior done/not done here?
Shared agreements kept/not kept by him?
Shared agreements kept/not kept by you?
Shared agreements kept/not kept by her?
And the consequences? Are you each willing to be held accountable to each other or not in this triad?