an inflatable mattress, said inflatable mattress defining a distal portion and a proximal portion, said distal portion defining a recess,

an inflatable housing defining an aperture, said inflatable housing being adapted to be detachably disposed within said recess, and

a massage apparatus disposed inside said inflatable housing, said massage apparatus including a motion driving unit for providing a simulated sexual action by a prosthetic member, said motion driving unit including a sliding block in operative engagement with a gear box assembly for providing said simulated sexual action by said prosthetic member, said sliding mechanism including an output shaft inserted through said aperture of said inflatable housing and being operatively associated with said prosthetic member for moving said prosthetic member in said simulated sexual action by said motion driving unit, wherein the inflatable nature and inflatable housing are inter-engaged sufficiently securely but with resiliency to provide elastic, resilient accommodation of the housing wherein the inflatable nature of support mattress allows rocking elastic and resilient movement of the inflatable housing carrying the phallic device providing safety and comfort to the user, while elastically resisting tendency for rotation in the horizontal plane, and protects against over-extension of such device, by permitting elastic/resilient yielding movement of the inflatable housing, wherein the inflatable housing is retained in the recess of the mattress such that the motion driving unit resists rotation, with rotation thereof in a horizontal plane being no more than slight, and yet permits limited rocking movement in a vertical plane, wherein the inflatable housing is retained in the recess of the mattress such that there is permitted slight/resilient yielding movement of the inflatable housing away from and toward the user seated on the mattress.