When he left.

Jason II

Jason knew Piper wouldn't be happy when he said he was leaving, but he didn't think she would break up with him.
Well, he wanted her to break up with him, but he didn't think she would.

And when he got to camp Jupiter to ask Gwen out, and he saw her and Dakota holding hands and giggling, he was ready to turn around and walk back into camp boarders and ask Piper to be his girlfriend again.

But, of course, it wasn't that simple.
Reyna said he couldn't go back until the Romans came for there monthly visit, which was a week away.

But when Jason got there, he never thought he'd see Piper wearing a glittering ring that he didn't give her, ( he had one in his pocket he was going to give her, but not anymore. ) and see her with Connor Stoll , snuggling up with a little 13 year old at the camp fire.

What hurt the most was that she didn't even notice him standing there.

Awesome right?
I would put more, but izzy's having an anxiety attack, so this is all I could write.

Bye
-zach