I have a girlfriend.. who I love and who loves me etc etc.. but I found out that her ex-boyfriend said that he still liked her.. she said that she doesn't like him.. and I do trust her... I just want some reassurance and some help...
Well, Chris, let me begin with a reality that sucks: in this game, there are no reassurances. What's worse, there are no rules; as we say here in Brazil, "Vale Tudo --" anything goes. The good news is that you can use that to your advantage!
But keep that UK stiff upper lip. My advice: remember what Sun Tzu wrote in "The Art of War." He said something like "don't do what your enemy expects you to do the most, do what he (or she) expects you to do the least.
Meaning, give your girlfriend a small amount of space but keep your eyes open, my friend. This way, she won't get the feeling that you're getting defensive and crowding her.
I also agree with the guys who say have an emergency escape strategy. Make some mental notes about who you might be interested in should the whole situation with your girlfriend go down the tubes. It's not a pretty thing to do, but it'll save you a lot of heartache.