It means they are an arsehole. This guy is talking about being a sadist pretty soon, he is going to want to do sadistic things to you.

@WendyG If someone likes to read such content does it mean that they themselves are sadist?

if he brings up soon after meeting you i will say yes. If he had bought i up all coy after knowing you ages, not so much.

Thanks for the clarification. You don't have to be that specific if you want to, mid 30ies is plenty of information. Btw, what is your goal as a response? Do you want him to stop asking such questions? Do you want him to be clear and open in his intentions? I don't know a person your age that wouldn't know what they are about. Don't share personal stuff if you are vulnerable in that area, but maybe giving a bit of background would be nice, e.g. why you think that you don't know what they mean (religion, no internet experience, ...). That would be a good starting point for an answer.

@Raditz_35 This may be a cultural difference. I am from India. I seriously don't know what he was up to. He is also from India. India is conservative when it comes to girls. Please answer in detail considering that I am naive. I am a software developer - if that matters.

That's a great way to clarify this. I know very little about Indian culture which is why I really shouldn't answer this - if the last sentence was aimed at me. But I think your last comment would make a generally great addition to your post, even though I do not see how your profession matters

@Raditz_35 please write an answer telling whatever you know about the subject. It may or may not help, but I will get to know a perspective.

I really do know very little about the subject, but I know women that are active in online communities and experience such people regularly. They usually just have a good laugh followed by blocking them. Really, there are more qualified people. But I wouldn't consider writing an answer anyhow unless you specify your intentions and goal because this might be off topic right now

@Aquarius_Girl nope doesn't change a thing, he answered in such a way as to pique your interest, to get you to ask follow on questions. If he wasn't proud of it or didn't want you to know he would have answered with another genre he reads, like "gritty crime", or "i don't really read much". He either wanted to shock you in which case he is a childish arsehole, or he wants to participate in which case he is a dangerous arsehole as he calls it "the darkside" not BDSM, so he is going to have no concept of limits or consent as limits and consent aren't "dark" and exciting

@WendyG Please avoid swear words. Thank you.