This article presents reflections on ethics in undergraduate mathematics classes in engineering in Colombia. It seeks to conceptualize ethics as forms of relationship with the other or as forms of alterity. In other words, since the production and learning of mathematics began, these are conceived as events that occur in human practice, and as the theory of objectivation suggests, ethics turns out to be an unavoidable element to consider. In this context, the first part of the article begins with a brief contextualization of the relationship between the teaching and learning of mathematics and engineering from an ethical perspective. In the second part, an approach to Radford's objectivation theory is shown, to describe his ethical position. In the third part, the design of an instrument is presented to explore with a group of university mathematics professors the types of ethics that may be operating in the classroom. The analysis of the responses to the instrument is shown in the fourth part of the article and, finally, some reflections and suggestions for future studies are described.