What does the '...' mean?

I dated this guy for 3 years. for the past year and a half its always been off and on with us, but never really workable. We've talked about one day having potential for a relationship that will last and prosper. Well we're at that point, and we tell each other we love each other no problem still. I'm just wondering what this means, which may seem kind of silly. I texted him saying I love him, and he sent back ':) you too...' I'm not worried about him not directly saying I love you, because he says that to me enough, I'm just wondering what the '...' might signify??