A great deal depends on the stage you are at in your life when determining whether to pursue a casual relationship.
There are other points in a person’s life when it makes sense for them to date casually, as opposed to seriously. For instance, a divorcee who is getting back into the dating game is advised to keep things light for a while, to avoid dealing with another serious commitment right away. Widowers may also want to dip a toe in the water, so to speak, and keep things casual until they feel they are emotionally ready to commit to another person.
Maybe you’ve been in a casual relationship for a 
while now, and you find yourself falling for the other person
Maybe you’re the one who wants to take things to the next level and announce your intentions to make this relationship more serious. How should you go about doing that? What are the best steps to take? And are you sure this is what you want?
With casual dating, there’s always that fear that perhaps the other person isn’t on the same page as you
Perhaps the most important thing to keep in mind is that you may want something entirely different from what the other person wants. Maybe you have fallen in love, but the other person is at a different point in his or her life where a casual relationship makes the most sense right now. For instance, a male student may feel he has found “the one,” while his female friend is more interested in finishing school and establishing a career for herself before settling down and having a family.
The first thing you should do is to evaluate your situation. Are you dating anyone else? If not, then you may already have the answer to one of your questions. This may indeed be what you want if you simply haven’t found anyone who measures up to the person you’re supposed to be casually dating. Ask yourself how you would feel if you were dating this person exclusively. Do you get butterflies at the idea of being this person’s one and only, or does the idea have you running for the door?
Delving a bit deeper, have you both gone through one or many struggles together, and you’re still dating? This is perhaps one of the surest signs that you might both be ready to take things to the next level. Couples who make it through trying times together have a better shot at staying together because it shows that they want to be with each other. If this describes your relationship, then it sounds like you may not be turned down if you proposed the idea of taking the relationship more seriously.
Other signs that you should turn the relationship into a more serious one may be staring you in the face. Look around your house or apartment. Is a majority of this person’s stuff already there? Is the person essentially living with you without living with you? If so, then it sounds like the only thing left to move in is the person.
A good practice in casual relationships is to regularly check in with the other person to ensure that you both are still on the same page, especially if you’ve been involved in a casual relationship for a while. Perhaps the other person has fallen for you and didn’t want to ruin a good thing by saying anything about it, but you may not want the relationship to head in that direction.