In my opinion, no parents should do things sexual in front of their children aside from hugging and kissing and showing mild affection. The steamier stuff should stay behind closed doors.

People in Vanilla relationships don't have sex in front of their kids, and neither should people in a bdsm or similar relationship. That doesn't mean you can't do it, you just have to be more discreet about it.

Before you had kids, you could do it anytime, anywhere. Now you have to wait until they're asleep or out of the house.