Siddra's eyes open a bit wider as the monster's cock goes into her wet vagina.  She moans slightly, but other than that doesn't really respond as she's focused too much on giving Mercution a blow job.  Glancing up at him she then looks around trying to spot the two girls but fails to see them, not surprisingly.   The blonde simply rolled her eyes at the lizard man's comment about his idea for a "game".