Meretricious

1. Tastelessly gaudy; superficially attractive but having in reality no value or substance; falsely alluring.
2. (law) Involving unlawful sexual connection or lack of consent by at least one party (said of a romantic relationship).
3. (obsolete) Of, or relating to prostitutes or prostitution.

(tastelessly showy): brassy, cheap, flashy, garish, gaudy, gimcrack, tacky, tatty, tawdry, trashy