I love messing with new parents
In what way do you mess with new parents?
I always tell them that they're doing a bad job.
It's complete wrong to make others feel bad about their parenting skills just because you think it's funny. New parents are under enough stress already, so you should do what you can to help them, not harm them.
Why are you getting so annoyed. They deserved it too.
I just don't think you should mess with new parents when they are probably already stressed out learning the ins and outs of parenthood.