Ever Put Your Foot in Your Mouth?

First off - I wonder how that saying came into being?  Other than a baby, who can actually put their foot in their mouth?  Just thought I'd throw that out there - maybe someone has the answer.
Back to the title.  Have you - opened mouth, inserted foot?  I certainly have.  Both times (there were many but these two are permanently engraved on my memory wall) were regarding pregnancy.
Yes, that's right.  I asked a woman about her due date and SHE WASN'T PREGNANT!!!  I remember where we were, what the weather was like that day and I even remember what she was wearing.  I quickly looked around hoping to find a hole in the parking lot that I could jump into.
You can bet your bippy that I never, never did that again.  I vowed that no matter the situation I would keep my big mouth shut unless the woman brought the subject up herself..
The second pregnancy faux pas was at a party.  Again, I remember where we were standing and who else was in attendance.  We were talking about having babies (this was several years ago - obviously) and I knew that one of the women in the group was pregnant so I said, "Wow, you are so brave to go for the third one."  Or something equally innocent.  She then told me what apparently everyone else knew except me; that she'd had a miscarriage. Again, I looked for that damn hole to swallow me up - nowhere to be found.
The next example I will gladly share with you happened to my dad.  I knew I inherited the trait from someone.
The scene:  standing on the beach, at the water's edge, in South Haven, MI, with one of his closest friends.  Both of them gazing out at the water, smoking cigarettes and slyly checking out the bathing beauties.  Dad glanced down the beach and said to his pal, "Purk, don't look now but here comes one of the homeliest women I have ever laid eyes on."  Purk did the slow, nonchalant head turn, paused for a moment before turning back to dad and said, "I would have to agree with you, Brach.  That's my sister."
Oh, I thought of another one.  Not me, though, so I'm thrilled this memory just came back to me.
The scene: a party.  A few men standing around doing the "man talk" thing.  One of them spotted a beautiful young woman across the room.  He'd never seen her before and she was a sight to behold.  I believe his eyeballs actually left their sockets - just like in a cartoon.  He asked the small group who she was and I'm sure there were some "guy adjectives" thrown into the question.  Once again, the slow head turn and one of the men declared the beauty to be his daughter.  Awkward.
I really think there's an aura or feeling that comes upon one as the mouth opens and the words fly out.  You can almost see the words and maybe you think about reaching out into the air to grab them. As if.   Or maybe you get that sick feeling in your stomach because you know you've just committed a horrid error.
So - naturally, I'd love to hear your stories involving your mouth and your foot.  I can't possibly be the only one out here.