read this joke sometime bk..
a guy wanted to have sex with his gf(who's a virgin) but the gal
refuse. in the end the gal agreed to give him a handjob but dunno
how to do it. the guy told her this.
"jus like when u r young, u shake a bottle of coke to spray at ur
friend"
so the gal did jus that. the guy started to scream, "dun put ur
thumb on the tip!!!" 
