It's really cute when little kids say, "What the...?" It's not as cute when adults say it, because we usually finish it with an expletive of some sort.
There are things you do not do. You do not trip old people. You do not lick other people's food. You do not put hamsters in the microwave. And you sure as heck don't grab someone's child without asking permission first. Especially when you are not friends.
Now, having lived in several countries with different social rules than ours, I know that it is likely that somewhere along the way, maybe even in Guatemala, a stranger will grab for, touch, or try to kiss my baby. It's one of the reasons that I like to 'wear' her in a sling- it makes it harder for that to happen. I also know, along those same lines, that people will always give me friendly advice regarding my child. For example, the other day we took her out walking in our neighborhood. It was evening and cooler than it had been during the day and I had her in the Moby in just a onesie. The next day, a kindly neighbor told us she saw us walking around and all she could think was, She needs more clothes on! She said this sweetly, but it was a direct hit. The thing is, my kid is a hot box. Even in the cooler evening air, we were both sweating by the time we got home. I kept feeling her head and her hands during the walk and would've taken her home immediately if she had been too cold. I do have some idea of how not to kill my child.
I have come to accept that things like this will happen. When they do, I will smile and thank the person for the advice. Or I will kindly ask them not to touch her or say, "No, you can't hold her right now," and everything will be fine. What I can't accept is someone who is not my friend grabbing for my baby. Not just 'not my friend' in the sense of not being close or not having spent much time together- those people I can tolerate. But someone who is not my friend because they chose not to be. Why would you think it was okay to hold my child? To hold my child after not even acknowledging my presence for an entire evening (which is fine with me)? Why would someone assume that was okay?
Because it's not. Nor will it ever be. If you touch my baby again, I will not only embarrass you publicly- something along the lines of yelling, screaming, just throwing a fit in general- but I could hurt you. I won't be able to help it. Blame the Momma Bear.
Now go play the victim. Tell everyone how awful I am and how you just wish we could be friends and, aside from nearly bouncing my baby to death, you didn't do anything to me... whatever.
You're an asshat.