<p>During sexual conflict, females are often compelled to mate with males despite the potential harm the males may cause them to ensure paternity. Males suppress the females’ re-mating potential by removing the scapus, a projection on the females’ external genitalia (i.e., external female genital mutilation [EFGM]). The present study is the first report of EFGM in the orb-web spider <i>Cyclosa mulmeinensis</i>, marking it as the sixth known species to exhibit this trait. Notably, although most oviposited females had mutilated genitalia, some mated females were unmutilated. To investigate whether mated females with a scapus retain the ability to re-mate, we examined the relationship between the number of insertions and the occurrence of EFGM in unmated females. The results showed that a minimum of two insertions were inevitable to complete EFGM. Additionally, females without a scapus had completely unsuccessful re-matings. Moreover, the frequency of successful mating in mated females with a scapus was significantly decreased compared to that of unmated females, indicating a sufficiently suppressed re-mating ability even when the scapus has not been fully removed.</p>