In this forum article, I reflect on the findings by Eva Silfver in "Gender performance in an out of school science context." Silfver has studied a class of 14-15-year-old students during a visit to a science center. The students are supposed to write a computer program that will steer a Lego car. In their activities, Silfver identifies ruptures of discursive borders that are immediately followed by recoups. I interpret the results as an account of forces disturbing the systems that justify stereotypes. I draw on Karen Barad to examine some of the moments in Silfver's study where a pedagogue is involved in reproducing gender stereotypes. Responsible intra-action is discussed in relation to gender performances and system-justification.