Difficult questions

So another day, my 4 year old son asks me:" how do girls pee? "
I was trying to quickly come up with a smart answer not to sound stupid but smart. So I sad:" girls do it differently, they have to sit". .and of course that answer did not satisfy him and says:" I know that but how if they don't have peepee..:-)
Let's the fun begin..
And this morning while getting ready to school..  He says:" mommy, I don't have a girlfriend yet..." yet..?! I  said baby, you are only 4 years old...you have plenty of time..and then I asked:" does any of your friend have a girlfriend?! (hoping he says no)..
He answers :" no, but I want to have one..."
OMG...