Bubbie has you covered, be careful if you smell gas on a carbed bike, time to shut the fuel inlet valve OFF and check things out. In this case you may have caught it early enough.
The simple and easiest explanation is rich mixture, could have "burped" or backfired expelling extra fuel when starting the last few times. The more ominous and possibly more likely is the tank drains by gravity past the fuel shutoff valve (if old automatic, vacuum operated valve when running) the only thing stopping fuel flooding is the float/needle assembly, after that all the gas will overflow dumping gas into the air filter or much worse, fill the combustion chambers, bubble past the rings, pistons (flushing all the top end lubrication by the way) and diluting the oil in the crankcase.
If you smell raw gas in the crankcase oil...DEFINATELY do not fire up the engine lest serious damage result...! This can and does often happen without proper winterizing before hibernating the bike over 4 or 5 months parked with old gas, that is all it takes.