SO confused! Do i go out with him or not?!

there is this guy who i have known now for almost 4 years.
he has always fancied me, and i always said no when he asked me out.
which was quite often.
about 2 years ago we fell out of touch, and then in the last month or so we got in contact again and started chatting on msn and stuff.
at first it was kind of annoying because he got quite sexual, and made me feel really uncomfortable, so me and my friend pretended that we were going out in an attempt to stop him being so overly sexual.
then he guessed that we were pretending and i apologised [a lot] and said why i did it, etc... he apologised for getting so sexual, and now he is being really really nice and sweet to me.
he is now really good-looking, and i quite fancy him.
he still fancies me and has asked me out, has asked me if he has any chance with me, etc...
my one best friends reallly hates him. i am not sure exactly why, but she really really does.
and my other best friend thinks he is pretty egotistic, but actually really quite nice and good-looking.
one friend says "no way, dont even go there" and the other says "i would if i were you".
so what do i do?! who do i listen to?! i am just soooooo confused!!
i think i do want to go out with him. he is a year younger than me but thats not a huge problem.
any thoughts please?!

No you shouldn't. There.

yeah, but i dont want to upset my friend who hates him!! and yes, some perseverance lol!!

i kno lol.
and seriously, she does not want him for herself...she just hates him! lol
and i know this beacuse she is constantly saying "he's a jerk, he's a freak, he's sex-obsessed, i hate him...etc..."