Is it normal for my stepfamily to grope each other?

In this explicit video, we see a stepfamily that is clearly close and comfortable with each other. The mother-in-law, who is clearly in charge, is seen instructing her stepson to take his clothes off, while her stepdaughter-in-law watches with a look of excitement and anticipation. The mother-in-law then begins to touch her stepson's body, starting with his chest and moving down to his groin. The stepson seems to enjoy the attention, as he moans softly in pleasure. The mother-in-law then turns her attention to her stepson's wife, who is also seen to be enjoying the attention. The two women begin to touch each other, while the stepson watches with a look of confusion and arousal. The video ends with the stepfamily engaging in a steamy threesome, showing just how close and intimate they are with each other.