Judah and Tamar
And struck by Judah being gratuitously nasty.
Judah has sons, and he obtains a wife - Tamar - for his oldest son who is blessed with the name Er. God doesn't like Er, and smites him before he has time to breed. Custom dictates that the younger brother shall take his brother's widow and give him sons posthumously, but Judah's second son Onan doesn't want to play, so God smites him too.
There's a third son, but he's under age, so Judah has to wait for him to grow up before marrying him off to Tamar, still in this quest for Er's posthumous sons. Judah doesn't want Tamar sitting around eating him out of house and home if she isn't giving him grandsons, so he sends her back home to wait for Son Three to grow up. This isn't the most charitable option, but it sort of makes economic sense, I guess. We can forgive Judah that.
But in communicating the plan, Judah says: שבי אלמנה בית אביך. Go home, widow! That's not nice at all. He could have said plain old "go home." He could have said כלתי - daughter-in-law. But no. And in a society where widows are basically just a drain on resources, "widow" is probably rather like "bum" - not awfully complimentary. And in any case, the poor girl's lost two husbands and doesn't have any children, how do you think she's feeling? She knows she's a widow, for goodness' sake. Having God smite two husbands in a row is probably something one might notice. I'd bet she isn't feeling too great about all that. So yeah, widow. Judah doesn't need to rub it in. That's just nasty.