Complex sentence: Andy's feelings cause him to remain absent on Gwen's wedding day, and to constantly bicker with her husband Rhys; despite this Gwen's influence remains a decisive factor in Andy's begrudging trust in Torchwood.
Split into simpler sentences: Andy's feelings cause him to remain absent on Gwen's wedding day, and to constantly bicker with her husband Rhys. Despite this Gwen's influence remains a decisive factor in Andy's begrudging trust in Torchwood.