Men and Rebound Relationships?

Similar Situation

Hi,

My sad story is that my ex bf of 4 yrs started up with another ex gf of his right away. In fact, he was setting things up with her (flirting over email) before he officially broke up with me. To be fair, he only started the heavy duty flirting with her after I broke up with him. (I'd asked him back right away. There was a 6 wk lag between the breakups we each initiated.) I only know about this other woman because I went into his email.

We were going through a very rocky patch toward the last few months there, and it is clear to me that he did this because he needed consolation on feeling like our break up was inevitable. I don't doubt that he genuinely loved me, as he had always called me the "love of his life." And from what he's told me about her, although I know he has great affection for her, I'm also fairly confident that their affair won't last.

But I really do wonder what it's like for him. He's really not a bad person, but it's really hard for me to fathom how he can sweet-talk her, tell her he loves her, and sleep with her - just a few weeks after being absolutely crushed about our break up? Can he be aware he's using her? Is it possible he's not? Any men out there who've done something like this? Can you help me understand? Maybe most importantly - is it possible he's stopped thinking about me, and has fallen out of love with me so quickly?

Thanks in advance for any helpful insight. This forum has a lot of cool peeps.