In this scene the players will not actively attempt to create any audience response. If at any time a player makes you all laugh then they are removed from the scene and replaced by another ‘more serious’ player.
The players simply generate a scene as they would any other. Playing things a little bit dead pan. At some point the audience will find some element amusing and the player responsible will be switched out. If no one giggles at all hopefully you are involved in an enjoyable serious scene. Something that improv is very capable of. The built in gag of the game is that players replaced are usually the wrong sex, wrong height, or wrong race. Then things get even more amusing.
Intentionally switching sexes, etc.