Cwmbran Celtic FC, a semi-professional Welsh football club, have said they are "in shock" after Fontaines D.C. frontman Grian Chatten wore one of their away shirts during the band's headline set at Reading Festival. The club say a size 3XL shirt was passed to Chatten via a friend working as the band's monitor engineer, with staff expecting it might be worn backstage rather than on stage in front of tens of thousands of festivalgoers.

The green and white-striped shirt is part of a 2026/27 kit initiative in which Cwmbran Celtic partnered with four bands, including Super Furry Animals, Panic Shack and Loose Articles, alongside Mogwai, whose logo appears on the shirt Chatten wore. Sales support both the club and grassroots music venues, with 10% of profits going to the Music Venues Trust, and joint commercial manager Matt Jarrett said pre-sale orders have "almost doubled" since the performance. Chatten said he supported the initiative because of his affection for Cwmbran and for causes backing independent music venues.