Could teenage affair be transferred to an adult affair-he's now a married man

I've been with the Love of. My Life for over 10yrs. And although we had a serious 7yr itch I thought we'll be ok...I was wrong :( we were both cheated on. So he cheated in his relationships,as did I,until we met each other. Unfortunately I was still being a so-called player (I had just. been cheated on +he's older than me).. By the time he wanted to settle down I had just started my being hurt (making everyone pay for it) even though I knew I. My heart that he's the one for me. I thought we got over that sour note but I was wrong
It has been yrs since then but he finds a way to bring it up. Now For The Ex Girlfriend...
He told me in the beginning that they went out when they were 14/15 yrs old and it seems to have flourished into their adulthood. Every awaking part of the day he's calling or she's calling -he says they're only friends now but I have a strong feeling that the old feelings might've come up.
I STRONGLY believe that he's telling her our problems. He's the type of guy that flips over any male that I may meet and introduce him to.
Although she's married I know that she doesn't love him. I may not be able to prove it but I do believe that there is something more to this than we're just friends.