If you 'walk over someone', you behave in a way that shows no respect for someone's feelings or which forces them to do what you want. This phrase implies that there is a difference in power between the people involved. This is quite a casual expression that is more often used in social contexts. You may also hear the expression 'walk all over someone'. Similar in meaning to 'exploit', 'take advantage of' or 'to manipulate someone'.

1. William and Jenny need to be more strict with their parenting. Their children walk all over them!

1. If you don't learn to stand up for yourself, your boss will keep walking all over you!
2. Due to his inexperience, the teacher felt that if he didn't enforce a strict disciplinary code, the students would simply walk over him.