Thumbs up for incest.

[D]

No first cousins are legal, and I'm pretty sure the law on this issue is the same in the US as it is in the UK.

My sister in law is married toone of her first cousins -::bvomit::

Well, we're both right and both wrong. Its only in SOME STATES that First cousins count.

Turner, Jeffrey S. (1996). Encyclopedia of Relationships Across the Lifespan. Greenwood Publishing Group. pp.p92. wrote:

In all states, close blood-relatives that fall under the incest statutes include father, mother, grandfather, grandmother, brother, sister, aunt, uncle, niece, nephew, and in some states, first cousins. Many states also apply incest laws to non-blood relations including stepparents, step-siblings, and in-laws.