The Ignored Reality 

Call water as water.
And poison as poison.

Many people unfortunately, even knowing that their cousins are non mahrams, treat them as brothers/sisters, and so hang out with them, talk as though they are your brother/sister from the same mother, which is completely wrong.
The Islamic guidelines which is applied while interacting with a non mahram applies to interacting with the cousins as well.
>Talk only when necessary.
> Minimize the greeting and the general conversation to only what is necessary.

The Shariah Hijab which applies to us when being in front of Non mahrams applies to cousins as well.

Call your cousin as cousin.
A Non Mahram a Non Mahram
And a Brother/sister as a brother/sister.

And follow what the Qura’an and Sunnah say not what your culture says!