Zig Zagged: Bob is constantly switching modes. On one day he may swear off love entirely, while the next he has fallen helplessly in love. This goes back and forth for some time, before Bob finally realizes he is being dumb and decides to give love a chance.
Averted: Bob's love life is never brought to issue or is never discussed.
Enforced: This film is being produced by the Catholic church, and Bob is an adventuring priest who must remain celibate.
Lampshaded: "What are you going to do, Bob, be a single person for the rest of your life?"
After a painful breakup, Bob removes all female contacts from his address book and begins to distance himself from all female friends.
Bob has received some sort of Virgin Power, so he decides to take the celibate hero route in order to sustain it.
The woman who is deeply in love with Bob is finally able to break through his icy exterior and open him up to romance again.
Alternatively, Bob's friends get him, really, really drunk one night...
Alice tries to force Bob into loving him forever or else.
Discussed: "Bob, I know you think love is a waste of time, but you can't just give up."
Dave: "What's wrong, Bob? Not into girls anymore?" Claire: "Good for him! Romance is overrated anyway." Dave: "What?! Don't tell me you are..." Claire: "Asexual? Didn't you know already?"
Bob's existence without romance causes him to become a lonely and bitter person, which in turn causes him to lose all interest in his original quest, and he lives the rest of his life as a lonely hermit.
Bob is very clearly sexually repressed to an unhealthy degree, and is deep in denial about it.