Chofni and Pinchas, the sons of Eli, when they seemingly cheated those bringing offerings at Mishkan Shilo and cohabitated with the women who congregated at the Mishkan. (I Shmuel 12-17,22)
I think each case of that question deserve their own question.
What was Hofni and Phineas apparent sin? Did they sin? What did they do?
It seems that cohabiting with any women is not a sin as long as the women are not married to anybody. Cheating at offerings? Hmmm. Cheating seems to be sinning. (don't steal, don't defraud, don't get bribe, it's all in the book)
I am not a rabbi nor will I ever be. So what does the law actually said?