He will stop kissing you and move on to other things. Like trying to get you naked. That old saying about how sex is like pizza, that even when it's bad it's still pretty good, does not hold true for kissing. Bad kissing can be a huge turn-off

But there is hope! There are definitely signs that you're a bad kisser. Are you moving your head around like a bobblehead doll? Does he have to stop and hold your head steady like he's righting a ship? Touching his face too much? Biting his lip too hard? (Remember that old Southern saying that I just made up: "If his lip is swellin', your kissin' ain't jellin'.") Are you being too tentative? Don't expect him to do all the work. Using too much tongue? Too little tongue? Using your tongue like he's a giant ice cream cone?

Other signs you need help in the kissing department: Does he initiate, or are you always kissing him first? Is he quick to move on to kissing your neck, or any other body part besides your lips? Does he always kiss you on the cheek when saying goodbye?

Also, if someone is a bad kisser, I'm usually going to break up with them pretty quickly. You can only pretend to be into kissing someone for so long. And I'm not that good of an actor. If you're a bad kisser, you'll feel it. You'll feel him pulling away, both physically and mentally. His mind will drift to sports or if he's out of detergent or whether he set the DVR for 24. You'll get a distinct "I'm not into this" vibe. Most guys are not very good at hiding their lack of interest.  

Take your time. Intense, passionate I-have-to-tear-your-clothes-off-right-now-and-make-wild-monkey-love-to-you kissing will come in time. There's something to be said for slow, tender kissing. And teasing. Don't dive in and slobber all over him. The suspense of the kiss is often as good or better than the actual kiss.

Finally, if someone is a good kisser, I'll usually tell them. I like to be complimented, and it's nice to know you are both amazing kissers whose sparks cause fireworks to explode above you and fountains to gush upwards just like in romantic movies. So tell him he's a good kisser, and hopefully he'll return the compliment and avoid an awkward silence.