I am a descendant of President John Adams through his daughter, Rebecca. My children's father is a descendant of John Adams through his son, John Quincy. How are we related? Are we cousins? With a number of times removed?
I did not know my ex-spouse was related to me when we married in 1984. Even though many generations have passed, I would not have knowingly married a distant cousin.
Let's assume John Adams is your only common relative, found somewhere perhaps around 9 generations back. That would make you and your husband 8th cousins. If there have been a different number of generations between your husband's side of the family and yours, then he's your 8th cousin, removed by whatever the difference is in the number of generations. Nothing wrong with marrying a 8th cousin, you share less than 1% of the DNA from dear old great-great-great-great-great-great-great-grandpa.