Most Helpful Guy
It's OK if you can stand to be near them
Most Helpful Girl
Just because two people Breakup doesn't meant they can't and don't Makeup and that it is Goodbye, my love forever. And with an "EX" who Still Marks an X in your own softie spot here, dear, there may come a time, down the love line, Where... I miss having him in my life.
If you both are 'On really good terms and he's even said he wants me to be in his life,' then I see no harm in you both mixing some sweet music as even friends for now.
You both started out as besties and with this a Real Relationship formed, and perhaps by going back to the past with Beginning your Beguine as before, this time around, taking it slow with the flow, you can nurse and nurture a nice mellow friendship that just may Reap you another chance at romance.
Good luck. xx