Second cousin once removed dating
Marrying a second cousin or more distant relation is legal in all western jurisdictions and even marrying a first cousin in legal in about half the states of the USA. A cousin is someone descended from the brother or sister of one of your ancestors.
A first cousin is a child of your parent's sibling; a second cousin is a grandchild of your grandparent's sibling, and so forth.
The grandchild of your parent's first cousin in the child of your second cousin and thus your second cousin, once removed.
If you are starting with your parent's second cousin, then the grandchild is your third cousin, once removed.
Your mother's second cousin twice removed is either your third cousin once removed or your second cousin three times removed.It is never a good idea to get involved with a person is who closely related. Second-cousins are okay to date, still wierd, but okay. Chances are, they are smart and would agree that it is not okay to date a cousin. If you have a third cousin twice removed, you are that person's third cousin twice removed.You could damage your relationship with them along with your family. Your second cousin is someone whose grandparent was the sibling of one of your parents.Third cousins share great-great grandparents, so figure out which cousin is the fewest generations away from these ancestors.Then, you will figure out how many generations of different there is between this cousin and the number of generations you (or your cousin is, depending on who is closer) are from these great-great grandparents.
It is also possible that your second cousin's first cousin's first cousin is also your second cousin.