Gender-fair language has been the subject of much recent research and insufficient consideration has been given to the negotiations of inclusive linguistic norms in everyday interactions. We build on the concept of grassroots linguistic activism to propose that community norms and affiliation around shared values influence the use of gender-fair language. We test these expectations following a corpus-assisted discourse approach, analysing ten YouTube videos on sustainable period products and their comment sections. We focus on the highly cisgendered period discourse to explore the extent to which gender-fair language has infiltrated mainstream usage. We find great variation in the awareness of gender diversity in the data. Only when gender-fair language is used in the videos, trans and non-binary people openly participate in the commentary, suggesting that linguistic invisibility leads to actual exclusion. Shared communal values of inclusivity, on the other hand, form the basis of successful grassroots linguistic activism and foster change in language use.