Show (one's) horns phrase
The devil is typically depicted with horns.
To display one's wicked, bad, or malevolent character.
I have never thought that a nice guy like John could be so wicked until he showed his horns by beating his girlfriend brutally.
I asked my girlfriend wether she still loved me if I had showed my horns.
After showing his horns, he was ostracized by his colleagues.
The verb "show" must be conjugated according to its tense.
The origin of this phrase is not clear.
A humorous way of saying that what one has said is just what they acknowledge and may not be entirely accurate
Mike: Have you returned from your vacation on the beach? Your skin seems to get tanned.
Jenny: My skin is always dark. That's my story and I'm sticking to it!