Whether you are asexual or your partner is, having that first conversation can be a daunting task. Many asexuals are afraid of their partner or potential partner's reaction and with so many misconceptions about asexuality out there, there's no telling what they may believe, assuming they even know what asexuality is. The most common reaction is, "what's that?" This puts the extra burden on the one coming out to be able to explain and convey exactly what asexuality is, in addition to the stress and fear of judgment they may already be facing.
It's Important to note, everyone's experience will be different and I don't want to presume or discount anyone's experiences. This is purely based on my experiences, and the experiences of others I've talked to.
Coming out to a partner is a scary thing. Whether it's someone you've known three days or three years, there is always that underlying fear that once they think sex is off the table, they're done. Sometimes it's hard to take that chance because really, you're opening yourself up to being told that sex is more important than you are. That all they were interested in was sex. This can be devastating, emotionally, and mentally, it's hard to hold onto your confidence in yourself when you are reduced to a sex object, especially by someone you care about or even love.
Of course, this isn't the rule, there are plenty of people out there that are willing to compromise and understand that asexuality is not a thing you control, but a part of who you are. But this doesn't make it easier to tell your partner in the first place. If you are sure of your sexuality, though, waiting does not make it better, stretching out the inevitable does no good and can hurt your partner, they will wonder why you didn't trust them enough to tell them or feel like you've been lying by omission.
If you aren't sure yet about your sexuality, it's ok to wait and figure it out. If you feel comfortable talking about the process with your partner that's great but if not, don't feel pressured to "come out" if you're not even sure that you know who you are.
The best policy is to be upfront with people, and I don't mean walk up to your crush and say, "Hey hot stuff, I'm asexual but want to go for a drink..." I have found that the best time to talk about it is once you're comfortable with each other, a few dates in perhaps, but everyone goes at their own pace, definitely before you have sex though (if that's something you're open to.)
When you approach the conversation make sure you have a working knowledge of what asexuality is where you are on the spectrum. You don't have to know everything, but chances are, you'll find yourself having to explain what exactly asexuality is to your partner. Make sure you're clear on your personal stance as well as asexuality in general. If sex will never be something you'd consider, tell them that, if sex is kind of meh, but you'd consider it with certain compromises, tell them.
The goal at this point is to get on the same page, talk to them about your feelings and needs, and let them talk about theirs. Once you understand each other, you can find common ground and begin to compromise. Communication is important in any relationship but especially one like this. Hopefully, you will be able to talk to each other and find a compromise that works and that is comfortable for both of you.
If your partner is not receptive to the idea, then it's up to you to decide how to handle the situation. If you think it's just a first reaction, and they'll come around, then have patience and help them find research on Asexuality. Aven is a fantastic resource. But if they are hostile to the idea or to you then it might be time to move away from them. If someone can't accept you for who you are, they don't deserve you and you certainly deserve better.
If you suspect that your partner is asexual, or if your partner tells you they are, this prompts a lot of questions. To begin with, asexuality is characterized by the lack of sexual desire, however, like all orientations, it exists on a scale. While some asexuals will be completely against the idea of having sex, there's plenty that are open to it. Either way, their "opinion" of sex (opinion really isn't the right word when it's not something you choose,) is valid and must be respected.
If you're here because you suspect your partner is asexual, good move! Doing some research before talking to your partner is a great idea. That way you will have a clearer idea of what you are asking them. This being said, looking up a bunch of facts then bombarding your partner with all the reasons you believe they are asexual, may not be the best idea.
There is a good chance, if they are asexual, that they are trying to figure out their identity for themselves before talking about it. You should approach the subject gently, tell them that you've noticed a few things and want to talk.
If you have been reading this post from the beginning, you can see how stressful it may be for an asexual person to talk about their sexuality for the first time. By doing research and being as understanding as possible, you can help and assure them that it's okay to talk about it. It's important to understand, though, that their experience will be unique from anything you read, so listening to them and letting them tell you about how they feel is very important.
Coming out is an important and very personal experience. Any coming out will present its own set of judgments and challenges and coming out as asexual is no exception. Being asexual, however, is not something that you need to broadcast to the world if you don't want to. For some, it's a private matter to be shared with only a partner or no one at all. On the other hand, if you want to display your sexuality for the world to see that's great, represent with pride! Both attitudes are great and valid, you can have pride in yourself without telling anyone it's all about what makes you happy.