I think i'm in trouble...

My son just turned 13 in December and has his 1st real girlfriend. I thought it was cute at first, now I am not so sure. They talk on the phone or text eachother every single day, multiple times, so much so that I have put a limit on his texts per day. He says things like "hey baby" to her when they talk or text and just told me the other day that they have thought alot about sharing their 1st kiss and they both believe they are ready??? HUH?, WHAT? I realize that he is growing up and that he is going to experience certain things but I am just not ready to let go, not yet. I had my 1st kiss at 12yrs old and I can remember it to this day...it is something special that will stay with him for the rest of his life, are we really ready for this?