Enzyme polymorphism in Pgdh is a striking example of single gene polymorphism involved in sexual conflict in bulb mite. Males homozygous for the S Pgdh allele were shown to achieve higher reproductive success than FF homozygous males, while negatively influencing fecundity of their female partners. In this study, we investigate proximate mechanisms responsible for the increased reproductive success of SS males. We found that males with S allele copulate quicker, more often and produce more sperm. We also confirm the negative effect that S-bearing males impose on the number of eggs produces by their female partners, showing a clear pattern of interlocus sexual conflict. We discuss that this effect is probably associated with increased copulation frequency hence the S allele-bearing males seems to be more efficient in forcing copulation and/or detecting females.