A friend, English-speaking culture does not see a family relationship between those two people.
They call you their cousin also!
you call your mums cousin a 2nd cousin, because your mums cousin is her 1st cousin, wich makes your mums cousin your 2nd cousin.
The brother of your wife's cousin is also her cousin. You can call either of them "my wife's cousin." You are not related to them.
I guess you could call her cousin-in-law :)
That would probably be your cousin-in-law.
Why don't ya call him by your cousin name +jr.
You can call him Cousin instead of uncle.
cousin daughter
He is your cousin
cousin in law
Your great-cousin.
Your cousin by marriage.