Greek Members Dating Non-Greek Members

I recently heard that a girl who isn't a part of Greek life is currently dating one of our fraternity's President.

So, would they automatically receive special permission to attend parties/private events, or would they draw the line because they're technically not apart of Greek Life, depending on the organization? A possible little sister role within the fraternity?

Now, I've heard of stories in which couples received special permission just because they were dating a brother or sister, for parties at least.

On an extra note, I guess it all depends on who you know & how close they are with certain people in & outside of Greek Life.