When Should One Say I LOVE YOU?

Saying "I Love You" in a relationship can be a pretty BIG thing. Love itself is a very strong word. Nowadays, people throw the word around like a bag of pennies. I'm not saying Love is bad thing, but when it comes to relationships you have to know when is the right time to say I Love You to your significant other. One shouldn't play around with the four letter word. If someone says they LOVE you, you want to know if it's for all the right reasons and not the wrong. 

Most of us have been down that road where we were in a relationship and our boyfriend/girlfriend told us they Loved us. We stayed content and happy until something bad happens; cheating, betrayal, and lack of trust comes along. Then there's the bad breakup; your heart is broken to pieces. How can you trust someone who say's they Love you and then have them cause the relationship to go sour?  

Not taking away from the subject on when should one say "I Love You" in a relationship, but you have to always keep that first heart break in mind for the next relationship or two. I just want to know when do you think it's a good time for one to say "I Love You"? Do you think it also puts pressure on a couple when one party talks to the other about the word Love? What is your definition on the word Love? How fast is too fast to say "I Love You"? Matter fact, when should the word "LOVE" be talked about in a relationship? If your significant other said "I Love You" would you ask why? Remember enjoying someone's company doesn't mean LOVE. I just want to know what you think about the word, because as scary as it can be I remember someone telling me they Loved me so much they would take a bullet for me.