It really sounds as though you are so focused on "no sex!!!" that you are the one who keeps bringing up sex-- by saying you won't have it. Your emphasis seems to be on making sure whoever you're talking to isn't going to try to have sex with you-- that you've lost sight of the real objective, which is getting to know the other person. It's often a better strategy to just NOT bring up sex AT ALL and, if the guy you are talking to brings it up, THEN say "I do not want to discuss that; I don't discuss sex or have sex until I'm in a relationship." And leave it there. Don't freak out, don't insult him, don't get angry, don't swear, don't accuse him of only wanting you for sex, etc. Just say very calmly: "I don't discuss that until I'm dating someone seriously." THEN, if he brings it up AGAIN after you've said that, then you can write him off. But it seems your reactions are disproportionate to the situation-- it's fairly normal for someone you're talking to from an online dating site (which is where I'm assuming you met him?) to bring up something about romance/sex as part of the process of flirting. I don't think that means he ONLY wants sex-- I think it means he's trying to get to know all sides of you to decide if he is interested in meeting you for a date. However, if he wants to have detailed, explicit "sex convos"-- like cybersex or kinky, dirty talk-- then I think that's enough of a reason to say "I'm not interested; sorry." What I find confusing though is that you said "there will be no MORE sex convos"-- which indicates that you willingly participated in these conversations? If you don't want someone who is looking for sex, then why would you participate at all in "sex convos?" That is definitely sending the wrong message and would be understandably confusing for a guy.

I've done my share of online dating in the past, and I can say that I've never had a problem with people bringing up sex too early or only wanting sex. Yes, I've gotten first messages that are a bit too flirty, but I delete those without responding. Anyone who takes the time to send me a detailed message, talking about we have in common or asking me questions about myself, has turned out to be genuinely interested in getting to know me. I think it's usually pretty easy to tell from a first message what they are looking for. I think there's a good chance that you are either (1) on the wrong website-- which site do you use? Are you on a hookup site or something more like match.com? (2) you mistakenly assume that everyone only wants sex and find typical flirting to be evidence that the guy only wants sex, or (3) something about your profile, your language, or your behavior is sending the wrong message-- you're giving off the impression that you do want sex, so that is who you are attracting. Even saying something like "I do not have sex right away!" sends a bad message because it makes sex front-and-center when it should not be. It's bringing up the topic of sex too early. Personally, if someone I was talking to on an online dating site said "Know that we will not have sex right away!" I would probably stop talking to them because I'd think it was really weird, kind of angry sounding, way too presumptuous about MY intentions, and I'd wonder "Why do they think they need to tell me this? Are they trying to change their promiscuous behavior? Do they usually meet people that DO have sex right away?" It would scare me off. I'd wonder why this was one of the first things they are telling me, rather than talking about their job, their family, their hobbies, their interests, etc.