They may or may not love you back the way you do.. Expecting back what you give away whole heartedly is not love for me, love is not completely barter..
But yeah, I would certainly expect a happy feeling for myself for doing something good, for we are alive to be humans, we are just doing that..
One may get bad experience, one may feel that they are not being loved back, they are not getting what they expected.. But that shouldn't end love for someone..
If you think once to yourself as why you fell for him/her in first place, you may notice that that feeling never goes away.. Whatever may happen, if you really feel connected to someone through your soul, it shall be so always..
And yeah, if you are not being loved back at all, one may walk away in agony, may plan to never come back, but once they look back at him/her, love just melts them again..
To truly understand what you feel in your heart for the other at any situation is the real love, may it be in form of any feeling for the time being.. But you just don't stop loving them ever, you just can't.. You still keep giving back the happy feeling of love to yourself.. And that's really cool I guess.