When to love?
You never love a person not unless he/she is important to you. You love a person for a reason and you will always love that person at least forever. When loving someone who loves you too add giggles. A magical feeling that you don't want to end it or like to freeze the time to be with your love one. There is a sense of underlying oneness which will lead to something blissful.
But when do you stop?
When you say you love an ex, this is pretty alarming. This is not good if you are already committed to someone else. There is someone else involved and you are hurting that person. Stand what you believe and feel. You cannot have the best of both worlds. You are being selfish and insensitive.
Sometimes you decided to end the relationship because you have to. You may not fully understand everything but you need to for the betterment of your partner or for each other. But the hurt will never fades. It will take you months, years to let go, to outgrown the feeling of not having the love you once had. But how will you know if it already faded? Sometimes people usually hid these things because the more they talk about it, the more pain they received. Finding another love is a very effective outlet. That person heals your pain at the same time you find yourself someone else that will break your heart. =(
Love is a wonderful feeling. Who would decline a love proposal? Greater chances no one will, yet about 10 - 15% might be. When love you felt is true, you can never go wrong but it is only wonderful when you are not hurting someone else. Don't be such a hypocrite. You don't have the right to play games with emotions. Aren't you ashamed of what you are doing? sigh