Is it possible to fall in love with someone without being in a relationship? It's possible but no. In my experiences, personally no.If you say yes, you need to ask yourself what it is exactly you are falling in love with.
There are levels of intimacy that can't be reached through friendship. There are character traits we can't see as just friends, but are very important in a long lasting relationship.
Is this person patient with you? When you make a mistake how do they handle it? If you have a disagreement do they scream, yell and curse or do they try to compromise? What about understanding? Girls, today are career women. Will the guy be understanding of her schedule and not harass (or complain) her to spend time with him? What if she has a child, will he understand that her child comes first?
Let me break it down.
Romantic: Sure romance may not be necessary, but you would like some thought into birthday, Christmas, anniversary and random day gifts and outings. At some point you'll want some level of romance.
Temper: How does he handle problems? Some guys are on their best behavior when courting a female, but once together they'll throw tantrums (amongst other things) It's very important to know how he handles his anger, because it may lead to physical abuse down the road, especially if he likes to resolve disputes with violence. How does he handle arguments with you? How doe she handle problems with others? Is he a problem starter or problem solver? This is important to me, because some guys like to escalate small problems. Turn them into a huge issue. I can come up with a million examples but so can you so try to remember a time someone got mad for something minor and insignificant. Will he be the same way or will he try to come up with a solution? Nothing annoys me more about men than trying to resolve every problem with violence.
Compromise: A good one. Couples will disagree on many things, it happens, same way friends disagree on things as well. Will he compromise? Compromising means sacrificing a little. You both need to give up a little to reach an agreement. Will he simply spend his time arguing his side or will he suggest a way to avoid arguing with you so you can both be happy?
Then there's the others like is he caring, loving, affectionate, thoughtful and my other big one...
Is he happy to have you as his girlfriend? Okay not a character trait, but it is important. I had a girlfriend once who was ashamed to be seen with me in public. As friends it wasn't an issue because she had no romantic connection, but holding hands in public was out along with everything else. We seemed more like a couple as friends than as an actual couple! Will he be the same? Actually in this case the question should be asked to females since they seem to care way more than they should about what others think.
Patience: A favorite of mine as well. If there is one thing people need it's patience. Too many people "snap" at you over dumb things and it's one of the reasons couples argue so much. They lack a tremendous amount of patience and it takes a lot of it to maintain a successful relationship.
Faithfulness: Will this guy be faithful? You won't be able to tell if the guy is faithful unless you are with him.
Communication: The reason most couples fight. Lack of communication. People don't like to talk things out in a calm way these days. Yelling is a form of communication however it doesn't solve anything and it's the worse kind. You should feel comfortable with a guy who you can talk quietly about your problems with, who will listen and consider your point of view. You need to do the same. Don't let anger fester. If you can't talk to him about something that bothers you this will be a huge problem. You should have a Full House type boyfriend not a Jerry Springer guy.
Love: Will he love you? Will he show that he loves you? At the end of the day we all want one thing, to be loved....BACK!
Family: To some females family approval means a lot. As friends you don't need family approval. As a couple you hope your boyfriend and family get along. There's nothing worse than excluding your partner from family events. If my family takes a one day trip to some city I'd like my girlfriend to come with. I'm sure you'd like the same with your boyfriend. They don't need to get along like a long lost son or become bff's. but if they can respect each other enough and find some common ground then all should be okay.
Point is that it is virtually impossible to know these things about a guy unless you are in a relationship. Some of these you may find out as friends but you may not spend that much time alone with the person to find out.