Oh my

[Sonia]

an expresion of suprise.
a response to a suprising situation/coment/picture.
a conversation scapegoat.
a sarcastic reponse.
see [oh dear]
see [jonathan costa]
an old person term.

[Jason Yan]

A meme-level expression used in response to anything sexually pleasing/enticing, whether it is an image, video, song, or written content.

It is most commonly used as a simple image macro featuring George Takei; the meme itself probably originated from instances of Takei saying Oh, my! in response to sexy stuff, especially on the Howard Stern show.

[Jason Yan]

Exclamation of surprise