Senators vetting the nomination of Pete Hegseth for defense secretary received an affidavit Tuesday from a former sister-in-law alleging that the onetime Fox News host was abusive to his second wife, to the point where she feared for her safety. Hegseth denies the allegations.The sister-in-law, Danielle Hegseth, was formerly married to the nominee’s brother, and in an affidavit obtained by The Associated Press, she said she believes that Pete Hegseth is “unfit” to run the Defense Department based on what she witnessed and heard. She said she first relayed her allegations to the FBI in December but was concerned that the information was not shared with Congress as senators consider Hegseth’s nomination to lead the Pentagon.The affidavit describes Hegseth’s treatment of his second wife, Samantha, and alleges repeat drunkenness and a domestic situation where Samantha Hegseth had a safe word to indicate if she was in danger at home. Danielle …