"Asexuality" isn't an orientation. Not in the same way as hetero- or homosexuality. If you're romantically involved with someone and you're having sex with them, then you're sexually attracted to them. If you're romantically involved with anyone, you are by definition sexually attracted to them, at least a little bit. That attraction is one of the things that drew you to whoever it is your with. When you look at someone and determine that they're "hot", that's sexual attraction. Assuming you aren't working as a prostitute (you as a general label, not *you* you), you're either an idiot or an a**hole for having sex with someone you don't think is attractive. Or very drunk.
Please, don't give yourself vague and nondescript labels like "panromantic asexual", it makes you sound like a 16-year old Tumblrina who wants to stand out and be able to call herself LGBT, but still get away with dating boys.
For starters, I'm extremely surprised that the idea of casual sex is something you have never heard of.
You are the exact problem with the LGBTQ community. The simple THOUGHT that I wouldn't have kids prompted my mother to yell at me and tell me to "never say that again". Even if I did "date boys" and I was asexual, that is not the same thing as being straight and it is being a member of the LGBTQ community because you still have to put up with **** like this. People thinking that you're a jerk for "pretending" to be queer in order to be unique and fit into the community because in reality they don't have to go through any hardships when actually, they do. That's an extremely despicable and judgmental view of something you have no knowledge of.
I am aware asexuality isn't a sexual orientation, but rather the lack-there-of, but it still isn't something you can control. There are different types of asexuality. People who find sex gross, people who have no problem with sex but don't feel the need to have it, and people who have a sex drive. Let it be known that having a sex drive doesn't necessarily mean you have casual sex. Calling people like that overtly drunk or ******** is essentially the same as saying that all bisexuals cheat on their partners.
It is important that I'm a panromantic asexual because "asexual" doesn't entail much. I can be asexual and still experience romantic attraction. Sexual and romantic orientation don't necessarily have anything to do with each other. In fact, a person can be romantically attracted to woman but sexually attracted to men. It's not common, but it happens. I'm guessing you're going to say those people are sickos, though.