Jennifer Lopez had a little accident

That headline makes it sound like she pee'd on herself, and who knows maybe she did (I do, she did), but while Jennifer Lopez was singing one of her incredible hit songs last night at the O2 in London, her dress stretched a little too far (oh I wonder why that happened) and you could see her nipple.

And it's weird looking. I've seen nipples before-mostly on TV but also in person-and they don't look like this. That looks more like ET is peering out of her dress.

(image source = pacific coast, getty)