It is a red flag for you but not so much for him.
He is not ready to settle down and wants to play the field. He is being honest, for which I give him points for that.
You need to decide if you wish to be his f-bunny, and just enjoy sexual drugs released or if you want more.
If you want more, find someone else, you will not be able to reel him in.
Also assume he has slept with half the school, so use a condom and get on birth control.
What does he really want?
He wants to have sex with you but not have to bother talking with you about anything.
Well since you are not a hideous creature you can assume 95%+ of the 18 yo guys you know feel the same way this guy does. Even the Christian guys you know who say they want to wait until they are married feel this way. Sounds pretty normal to me. The only abnormal part is what Shane said above. Most guys don't come out and be so blunt about it.
Most guys won't come out and be so blunt, with someone they know is actively pursuing chastity as a lifestyle. My guess is, she let him know she was crushing on him, and he's too busy being a manwhore, he let her know what he was after so she would stop.
One of the last posts here made me think of something to add. I get the impression that the OP doesn't have the kind of relationship with her parents that would make her feel comfortable talking to them about this. And I don't know what part of the country she lives in, and what kind of sex-ed they give the schoolkids there. So here goes some "Before you Become Sexually Active 101"
1) If at all possible, talk to your mom or your dad and let them know that you've made the decision to become sexually active. I understand this may not work for you, but if you have a parent that will have your back, that makes everything so much easier.
2) Get a checkup by your gynecologist, and have him/her prescribe a method of birth control. I don't know about how it works wherever you live, but around here, if you're 17, there would be no need for the doctor to talk to your parents about it. The pill is the most effective method open to you, but you'd have to be disciplined about taking it EXACTLY according to the instructions. If you do, it's better than 99% effective. If you don't, it's not even close.
3) Insist that your partner use latex condoms to prevent disease. Condoms aren't nearly as effective as The Pill for birth control, but The Pill does nothing to prevent disease. And the diseases are nothing to fool around with. AIDS is forever. Condoms + The Pill, if used correctly, is close to 100% effective for birth control, too.
This is ESPECIALLY important if you're contemplating being sexually active in a casual way, possibly with multiple partners. Remember that you don't just sleep with your partner, you sleep with all his partners - unless he's as careful as you are, which you have no way of knowing with a casual partner (no matter what he tells you.)
In a more committed, monogamous relationship, (which doesn't have to be marriage, just something where the two of you are committed to being together exclusively, at least for a while), you can both get tested for the nasty diseases, and that can loosen up the condom requirement, provided you are absolutely RELIGIOUS about taking your birth control pills. Otherwise, stay with the "suspenders AND belt" method - it's good to have two lines of defense.
4) Decide, before you become active, what you will do if something happens and items (2) and (3) above don't work out. Will you keep the baby? Put it up for adoption? Or seek an abortion? Make sure you know how you feel about those three options, because they're the only three there are when you're pregnant. Being an 18 year old mother, wed or unwed, is a pretty bad start to life. Don't wait until you've missed two periods and are frantic to decide what you'd do.
Also - don't count on an 18 year old boy, no matter what he says or how committed he says he is - to be much help if you get pregnant. It will be pretty much on you to deal with it, unless you get extraordinarily lucky. Don't bet on getting extraordinarily lucky.
I think it is normal for a young guy to feel like this, but to express this is different. He seems to want a stable of women who he can "keep company" with and have no responsibilities or comitments with. This is a serious lack of respect for women in general, I think he is fishing to see if you would be one of these women.
HUGE RED FLAG, FLAGS, PARADE OF FLAGS
How do you know he's looking for a "stable" of women, or is showing lack of respect? We only know of one woman he's approached with this proposal, the OP. As I said above, one of my dearest lifelong friends and I had that sort of relationship forty years ago, and we both respected and still respect one another a great deal, and even though she lives over a thousand miles away now, we still talk on the phone, keep in touch on FB, etc. We both went into it with our eyes open, not expecting it to be anything other than what it was, and it was really nice for both of us at the time.
I think you're right that he doesn't want the commitment of a romantic relationship. But I don't think it's necessary to demonize the young man - he's letting her make the choice, and we haven't heard anything to indicate he's being coercive or abusive in any way. There are women who are ok with a "friends with benefits" relationship, and don't want the baggage of a romantic relationship either. It's not a lack of respect, it's just a matter of wanting what he wants, and feeling her out to see if she wants the same thing. If not, then still friends without "benefits". No harm, no foul.
The only harm would come if the OP goes into this sort of arrangement unprepared, or expecting that he'll "come around" and fall in love with her. Then she's probably doomed to being badly hurt.
I feel that he is approaching a person who he feels may entertain a relationship like this, Your situation is so much a rearity that we are talking about it right now, I dont thik it is typical of how these relationships go as you have already stated. This is not the type of relationship a father wants his daughter to have, a brother wants his sister to have, or a man wants his future spouse to have had. I am a bit more traditional, or conventional, or old fations etc.
It is fraught with many hazards that you have already stated, if he is able to get one girl to agree to this type of relationship why would he stop at onely one? As this would not be a monogamous relationsp how many other women will he be with at the same time? Why would he respect her? Not knocking your relationship or friend but I would be hard pressed to say I respect a woman who makes herself readily available for sex only. A woman should be the image of virtue, self respect, decency, and nurturing (again traditional). Not saying a Nun, but someone who is at least selective enough not to allow some 18 year old kid romp on her as is convenient. While three years is not alot of time, there is a big difference from 18 (this kid) and 21 when you started your relatinship. I suspect you would be in a severe minority of those who have had a relationship like this that did not end catastrophically.
I am not attempting to be disrespectful or sarcstic. If there is any offense it is not intended, these are only my impressions and opinions.
He's a cad. My suggestion is to let him know, in whatever words you feel is most appropriate for you, that you are not interested being a trollop and that if he can not respect you any more than that then you have no interest in having him in your life. Now, he is going to retort with assorted reasons as to why he really does respect you and why he wants cheap, meaningless sex. Don't buy it, don't even entertain the discussion. Cut him off mid sentence and tell him you said you are not interested and that it's the end of the discussion.
He wants easy sex. I'd forget his name if I were you.
Can't say I've ever heard the words, "cad" and "trollop" used outside of a cheesy Victorian costume drama before... lol
The general consensus here is correct, Chrissie. He wants sex, but doesn't want the responsibility that comes with a relationship.
Is it normal? Yes. That doesn't mean it's alright. You know the answer yourself, based on your original question. He doesn't even want to be your boyfriend.
Walk away. Be firm. It's not just a physical act. There's a whole lot more that comes with a sexual relationship.
Find someone who shows more respect for you.
It is pure sex driven desires, thats all. As for you stay away from little immature boys wanting to play daddy instead look for yourself a real gentleman one that would treat you like a queen, respect you and love you for what you're worth...more than gold. I've learn the hard way do not let that be your teacher.