Mi prima y su esposo.
You could say "No mucho, primo" (Prima for a female cousin)
Your cousin's husband is the spouse of your cousin.
Your wife's brother is your brother-in-law.
You are not related to your cousin's husband. He would simply be "My cousin's husband."
prima = cousin who is a girl primo = cousin who is a boy
Your husband's cousin's sister is also your husband's cousin. You are not related to your husband's cousin.
primo Juan
hola primo
De tu primo(a)
In genealogy terms she would be "spouse of your first cousin."
You could say "¿Conoces a mi primo?"
Your cousin-in-law.