So your fella isn't paying as much attention to you as he should? Well, have a I got a system for you*.
Nothing says "Pay attention to me." like a borderline indecent skirt and indignant stamping of feet. When and if that fails, simply drop everything. Literally, and preferably in the middle of the street (watch out for oncoming traffic**). Begin whimpering. Pouting, although effective when face to face, is silent. Even if said fella manages to make it a few blocks without noticing you (because a girl in an even shorter skirt riding a bike rolled by) he will eventually hear your high pitched squealing which devolved from the initial wimpering. Keep going. It's working. He'll roll his eyes, turn around and wander back in exasperation. He's pissed off, and you look like a Grade A Imbecile. Success!
*disclaimer: this does not work.
**although speaking from personal experience an impromptu hospital stay can really solidify a floundering relationship.