First of all, Pua are the worst for relationship advice.
I do not care if a girl is talking with her ex or perhaps fucking them, because im too busy getting other girls to bed.
In your case, remember dont let the noises drown out your own voice. You dont need to care about facebook messaging. Horny guys will always try what they can to get laid. Instead focus on how to improve your relationship in different ways like more cool dates and maybe travel together.
And one more thing, make sure you and your gf have a healthy boundary. couple things include in this.
1-dont see each other too much, its for your own good, you will get more things done and less bored of her.
2-The time you are with her make sure is quality time and encourage her to share her emotions with you.
3-dont be jealous of some random people.
Here is a video to abetter understand my point
http://www.youtube.com/watch?v=wxWuREjuLAE