Who wanted sex has no impact on current
relationship; which means if you are with him and you wanted it,
there are no qualms about it if you are comfortable and know what
you are doing.
I already explained why he did tried to screw you, despite his
original behavior of rejecting your desire in the past.
In short: Time change, people change. Guys don't mind screwing
girls that don't belong to them and you can be surprised
how rigid they could be with their actual love.
This is so terrible. How you can be so easy with yourself and
constitute your action by saying that you didn't know what was
going on? It means RAPE if you are unwillingly and the ultimate
question remains: ARE YOU? My dear girl, you can't just let things
happen, avoid and say 'I dunno what's happening.' Psychologically,
when we are lost, we revert back to our childhood behavior; we dump
our trouble, hoping that everything will vanish and
something/someone will take care of the mess...
THIS WILL NEVER
HAPPEN.
If we were to see this situations in ways of the animal kingdom:
You, the female, dropped subtle seduction messages that he picked
up somehow and instigated his lust. There are many issues that you
would have left out and these are your little clues that would
contribute to this fateful event.
Advice? 
Avoid reverting to childhood and resume being an adult - the one
that does what they need to do because there is no one else to
clear the sh!t. This event was born from you, even if you have to
be in bad light or whatsoever thingy - that, truely, is just a
little punishment for you to gain enlightenment and wisdom.
Consider the following options:
I) Learn to love yourself, learn to grow up, learn to treasure
yourself. Continue current attitude and thinking is undesirable,
even if future relationship were to come - the basis of your
personality will bound to invite unwanted scenarios that would
drive you crazy.
II) You have to tell him. Seriously, what's going you back from
telling him? Because you don't want to appear as the bad girl in
the picture? You already have plans to leave him, even if you were
to tell him, it shouldn't change the fact (unless he loved you very
deep).
- Plan structure of your talk. This talk probably has a concluding
effect. Therefore, the content of your conversation can be long, it
doesn't matter. Most important, the things you wanna say to him and
the things he ought to know, add it in.
- Location important. Seriously, no meeting at each other's house.
Go somewhere quiet. A beach or park or something.
III) If this relationship doesn't last - avoid any form of BGR
within the next 12 months. Take this good opportunity to reflect
upon yourself. Borders and Kinokuniya has thousands of books that
you can read and they will bring your love wisdom to greater
heights. Observe others and most important; learn from where you
walked wrongly.
Cheers
