The patron even has his wife order flowers for me

I’m not a secretary, I’m an expert assistant, but my boss constantly reminds me of his wife’s birthday, has flowers ordered, or locks me into making payments for his child’s courses. I’m hesitant to say no because I’m new, but honestly, I feel very used; it’s unclear whether I came here to build a career or just to be an assistant. Do you think I should warn him sternly, or should I consider resigning directly? I’m not sure.