The idea of dating a friend can be a very sensitive issue, depending on one’s perspective. Therefore it should be taken with a little measure of care and thought, especially if it is a long time friend that considers you as someone easy to get along with.
If you feel something more than just being friends with her, or him for that matter, either your friendship may help reinforce or be an obstacle to that special relationship that you have in mind.
Friendship can either blossom into a special relationship or it can damage whatever relationship you have shared before. As said before, it will depend on how both of you look into the kind of friendship that you have. It is important that before you ever make any moves on asking a friend on a date, you should try to learn and know how he or she thinks about it.
You can either ask the question straight on or you can do it in various subtle ways. Either way, you need to get his or her thoughts on the matter. If you get a negative reaction, then you should think again if you think it might be worth the risk asking a friend on a date with you, especially one that carries a romantic inclination.
If the reaction that you get is positive, then you might need to have yourself prepared if the time comes to ask your friend on a date. This might take more effort on males since this might not usually go the right way even if the female thinks that dating a friend is ok.
It is important that you have to be clear enough when asking for a date. A confusing request such as, "Uh, can we, uh you and me, go out sometime?" may send confusing signals to a girl. The request can mean going out on a "friendly" date, which you may not want if you wish to make the relationship go to a higher level.
Be clear what you had in mind and make it known to your friend. "We have known each other for a long time and I find you very attractive. Can I ask you for a date?". This would make it clear that you wish to build up a more romantic relationship with your friend.
Now that you know how to ask your friend for a date, you have to prepare yourself for a reaction. You should be prepared for questions. You friend may not even thought about going on a date with you. You should at least try not to make her feel uncomfortable or pressured in getting her to decide at once.
Give her a couple of days to consider it and give it some thought. By no means should you try to pressure her. This will only lead to a rejection or strain your relationship as friends.
There are only two answers to your question. It could be a "yes" or a "no". You have to be prepared for both. When your offer is rejected, try not to take it personally. Yes, it may change your relationship in some ways, but you should learn to respect her decision.
Don’t take the rejection as a slap in the face that would lead your friendship to strain. Instead, take it as one that will make you realize that you are better off as friends. Just try to consider that fact that you still have a relationship and a great friendship is too good to waste.