Student teaching assistants have two roles simultaneously—students and teachers—which leads to inherent conflict of interest. This chapter shares the experience of the Faculty of Informatics, Masaryk University in Czechia, where ethics education is not obligatory for teaching assistants. Over multiple semesters, we conducted surveys on attitudes toward ethical issues in teaching practice. Based on the survey results, we developed the teaching toolkit on ethical dilemmas, including the framework for ethical decision-making. We incorporated it into the teachers’ education for computer science teaching assistants. We also developed a Code of Ethics for Tutors, which became an official faculty document. Altogether, these results help to raise awareness of ethical issues that student teaching assistants face and positively contribute to the culture of academic integrity. We discovered that computer science student teaching assistants are most hesitant about their relationships with students and conflicts of interest arising from their dual roles. Our findings highlight the importance of incorporating ethics into teacher education and increasing awareness of these issues across faculty. They can serve as inspiration on how to explicitly include ethics in the teachers’ education and raise awareness of ethical issues across the Faculty.