What would you do?

If someone called you and threatened you then told people you lied about the threat just for a day later to admit to threatening you and laugh about it saying it was a “damn good threat.” Long story short my in laws didn’t like something my husband and I came to them about (with something they said to our child’s teacher) so my FIL called me while my husband was at work telling me he was going to end everything and when I asked him what that meant he told me I better just think about it and hung up. I called my husband crying because I didn’t know what to do and of course my husband was livid so he reached out to his dad and his dad denied it. Then tonight when things really came to a head he laughed and said he did threaten me and it was a “damn good threat.”