Antonyms for the phrase "mixing it up with" include avoiding, separating, isolating, segregating, and dividing. These words represent the opposite of blending, combining, or interacting with others in a social, professional, or cultural setting. Avoiding implies keeping a distance from people or situations to prevent conflicts or misunderstandings. Separating and isolating suggest creating barriers or boundaries between individuals or groups to maintain order or control. Segregating and dividing refer to the act of separating people based on race, ethnicity, religion, or socio-economic status, which can lead to discrimination and inequality. Thus, it is essential to choose our words carefully and use language that promotes inclusivity and tolerance.