Remove duplicated pairs considering two columns with Pandas

Question

I have a dataframe

import pandas as pd

df = pd.DataFrame({"Name1":["John","Peter","Sue"], "Name2":["Peter","John","Peter"]})
df

    Name1   Name2
0   John    Peter
1   Peter   John
2   Sue Peter

I want to remove duplicated name pairs considering two columns, to give

    Name1   Name2
0   John    Peter
1   Sue Peter

A similar question was asked , but was on R.

I wonder how to do this with Pandas.