Been there, done that! lol
My advice to you would be as simple as this. Talk to her, and voice your concerns about why your worried. I've found that even though the things I have to say to my kids are not always what they want to hear, I'm talking to them. It has made a world of difference in our lives. It sounds like you've got a big part of that already happening. I know you dont want to crush her heart because of how excited she is and all by telling her you dont like the one she has chosen to go on her first date with.. but.... she needs to know. And it can be said with love and concern.
I think more importantly is talking to this boy and his parents. Regardless of his history with other girls and the way he or his parents have conducted themselves. It only matters now, with you and your daughter. I think at a young age girls are really sucked in by that bad boy attitude and it is a magnet for them. They really know it is not a good thing, but want to see if this person will be different with them, or if it is something that will be more exciting than always being the good kid.
My daughter (now 18 and moved out two weeks ago)and I have a wonderful relationship and I didnt allow her to date until 16 yrs of age, and sure enough the day after she had a boyfriend that was waiting in the wings for her birthday. Low and behold he seemed nice around her father and I, but we are both very intutive and very perceptive to picking up behavior and heart felt energy about people. I knew this kid might have not been the best decision for her, I voiced that, and said well, you need to always put you first. If ever there is a moment that you need to question what he has said or done to you, then do so and do not judge yourself for that. Go with your 'feeling' and not your head or you'll find yourself in a situation that you will have a very tough time getting yourself out of. She is a very strong willed, vibrant and strong young lady so I knew she would not have an issue calling him on something he did wrong to her. But, it would have to be her. We as mothers want to protect our children from all the bad in the world, and that includes them getting their heart broke. But, that is a hopeless unrealistic thing in our own minds. This and all experiences will need to be lived and learned by our children themselves. We only have the ability to appreciate their willingness to love and be loved, the ability to trust them in their decisions, the ability to communicate even if its arguing and discussing things that are not always comfortable, and finally the ability to be there for them and listen and hold them when they are living 'life' and 'feeling' the hurt, the happiness, the struggles, the successes. The greatest gift to us to have them include us in their journey and look to us for strength and guidance and a good 'ear' when needed.
Sorry to ramble, but I feel your heart aching from concern, and yet to want so badly to do the right thing in helping your daughter be happy and healthy. My big thing is to not always give the negative side of the person they are seeing. I've since changed my ways in thinking in so many ways since my daughter has grown. I have an opportunity again (i have another 13 year old) and can try and put things in a positive and non judgemental intention with her and her relationships with both girls and boys. It really is a struggle for them in all aspects. They are learning so much about themselves during this time. I have always taught my girls that the outside world does not define who you are, or what you should look like, or wear, etc. You are beautiful just as you decide to be, and you will attract the people that should be around you by being true to yourself. Speak and act in integrity and honesty and things will align themselves perfectly.
Another option for you going would be that it not be a date of just the two. Make it a date of three couples. This was a rule with my daughter to prevent the dating thing starting prior to sixteen. She went everywhere as a group. There were no one on one events happening and I think it helped greatly. So, if your able to implement her group of friends bringing their boyfriends or what and going all together that could be a secondary option.
#1 Talk to you daughter with your heart and not your head (no judgment or character assumptions) speak from a place of pure love.
#2 Talk to the parents (either on the phone, but face to face would be much better) about how you've raised your daughter, and the things that are expected of her while out on her first date.
#3 Talk to the young man about the intention he has on this first date. I would try and open up the conversation more along the lines of getting to know him personally and finding out what his values and goals are for life. It is entirely possible that this boy hasnt had the communication with his parents or anyone and therefore goes outside of the family to do things that are of acting out (losing virginity, etc). This might make all the difference in the relationships he has throughout life period.
#4 Trust yourself and love yourself for the daughter that you've raised. Love yourself for being a concerned parent and wanting to be involved in her life. Trust that she will do what is right, and will come to you when she needs your love and guidance.
Good luck my dear! let me know how it goes.. now that I've wrote you a novel.. sorry all. I've been on a heck of a spirtual journey and learned so much about the way I could have done things.. nonetheless.. my children have turned out fabulous and beautiful.. because the biggest thing I've taught them through all is that I am human. I am learning just as they are, we are going through this together and although it seems as if I should be the one to say all the right things, and do all the right things because I am the parent.. I am not perfect, I've never been perfect and I never will be perfect. I am in this school of life, just as they are. we are a team. Lets work together and love together and it is what it is!!
Blessings ~ Feel free to email me if you'd like to talk more.. I'm on the Eastside.. just south of you.. but, would love to talk more if your feeling anxious. have a beautiful day~