well when you maturbate it release's a very short dose of the chemicals we attribute to being in love. it might not be that you are falling in love, just that you are into this girl and are releasing the same set of chemicals so your urge to masturbate has decreased.

its kinda weird because some people can become addicted to those chemicals and are usually the stalkerish weirdo types, they excessively masturbate and attribute the feelings to their fixation, but the masturbation chemical breaks down and can have some really messy side effects. which is why we probably feel like shit when you break up with someone you love.

peace