What does this iphone emoticon mean?

What does this iphone emoticon mean?

Added (1). It is the icon of a boy and girl both smiling with a pink heart in the middle.

Is it used to symbolise a crush or dating/marriage relationship?

It could be It really depends on the conversation.
"I love you
"I'm watching the vow
"Lets go on a date?
You tell me? It sounds like flirting to be honest, I wouldn't read to much into it.

There's not set meaning so it really comes down to what you want to think it is so whatever you want it to be thats the right answer.

- I assume you mean that one. Yes, it symbolizes affection.

The iPhone (which can read those Emoji (not emoticon) btw) defines it as "couple with heart"