LOVE:

Clark is a very shy person; he loves Lana but he doesn't even try to talk to her about these feelings.
On the other hand, Lana doesn't love Clark, she likes being only his friend; she loves Whitney, her boy-friend.
Clark, isn't the only one who wants Lana, so do Greg, a bug-man. As Greg tryes to mate with Lana, Clark stops him and Greg accidentaly kills himself. All the credit from Lana's rescue is for Whitney, who pretends to have saved her life.
When Whitney crashes in his truck, Clark saves his life. Lex Luthor, Clark's friend told him that if he would had not saved Whitney's life, Lana would be his. But Clark would never think like this because he is a very loyal and good guy.
These things happen in our everyday life. It is common to love a boy/girl that has a girl/boy-friend; you just don't know what to do. In my case I think I'd have done the same as Clark, being quiet as his/her friend and wait to him/her gives a look at you.