Most Helpful Guy
That sounds sketchy. If he wanted to make things right with you and stick it out, why bother asking out another girl? It kind of sounds like he was trying to find another option, maybe somewhere else he could go, but when that failed, just opted to go back to you for the sake of convenience. But everything I just speculated is just that: Speculation.
I can't tell you what his motivation is. Maybe he's genuine. But from where I stand, that's a strange thing to do if you were always planning on staying with the girl you "love".
You could always ask him why he asked that other girl out. Hear what he has to say.