Either you had an enemy you thought was your friend and are dropping weight you didn't need to begin with, or you just lost the person willing to point out your shitty choice in men. Hopefully it's the first one, since divorce sucks. Hope everything works out!

Seems to me it’s likely one of two possibilities (or a combination): (1) Your ex best friend had a romantic crush on you and when you got married, that put the stake in the heart of their fantasy. Simple jealousy… (2) Ex friend thinks you are making a bad mistake. Does your now spouse have a troubled past? Regardless of the motivation that’s some pretty awful behavior on your ex friend’s part.