Three women, A brunette, a redhead, and a blonde, all come 
home from work at the same time and get on the elevator. 

The brunette notices a blob on the elevator wall and says: " 
OOOOOhhh that looks like semen." She reaches out and 
touches the blob with her fingers and says "It feels like 
semen."

The redhead reaches out and touches it with her fingers, 
smells it, and says "It smells like semen." 

The blonde,  reaches out and touches it with her fingers 
and then puts her fingers in her mouth and tastes it and says, 
"It doesn't taste like anyone in this building . . ."