Teyana Taylor is convinced Iman Shumpert's relationship with a woman is negatively impacting their children -- so much so, she wants an expert to get involved in their divorce ... TMZ has learned.
In new court documents, obtained by TMZ, Teyana asks the court to let her call on a child psychologist to testify about something she says went down a couple weeks ago, when their daughters -- 8-year-old Junie and 3-year-old Rue -- were staying with their father.