Do you believe in love at first sight?

Okay not necessary "love" at first sight, but like lust or when you see them you just know something will happen between you two and it does? Its happened to me once, and the second time its been happening with this guy in my class over the whole school year and its confusing but we've talked only a few times but I guess we would always "flirt" but its hard to explain but you can tell there is something going on he would make the most obvious glances haha and when I walk I smile and I cant help it(: Im smiling as Im typing right lol. I know it may sound cheesy or whatever but hey Im lovin it(: tell me your opinions. Please don't be rude(: