Not in good taste (5)
(Other definitions for unseemly that I've seen before include "Disreputable" , "Not proper or suitable, perhaps behaviour" , "Not becoming or fitting" , "Not decorous or fitting" , "Not in good taste, improper" .)
(Other definitions for tacky that I've seen before include "Cheap and garish" , "(Of glue) slightly sticky" , "Tastelessly showy" , "Sleazy" , "Sticky; showing poor taste" .)