Well if you go looking for trouble, you usually find it. If this is the only thing as far as other girls though since you have started to seriously date him then I woudln't read into it too far. We all have our pasts. If she were calling/texting day and night or he was giving you reasons to feel that something was going on with her that would be another story.
So, so you think you can tell Heaven from Hell,
blue skies from pain.
Can you tell a green field from a cold steel rail?
A smile from a veil?
Do you think you can tell?
And did they get you to trade your heroes for ghosts?
Hot ashes for trees?
Hot air for a cool breeze?
Cold comfort for change?
And did you exchange a walk on part in the war for a lead role in a cage?