I agree with CityGirl on this. There was no deep discussion on the reason for suing for full custody. She quickly got to your personal life and then the kiss. She's good, at manipulation, that is. Her answer for suing is standard legal speak.
But, I can see that you are stepping lightly and will not give up your half of custody. I don't think you should date her until you have a better and more complete answer to why she is suing you for full custody. For instance, she could give a reason as to why the kids would be better off with her? It's working right now, so why would she rock the boat?
Take care.
Me:57 H:52 M:28 Got another lawyer last year and filed. D35,S/D twins28,D22 EA4/04 End? Who knows? "Life is like a mirror. Smile at it and it smiles back at you." — Peace Pilgrim