I know you are probably quite hurt, but he isn't trying to hurt you...In fact, he's probably trying to make it as painless as possible for you...It's possible that he thinks it would be easier for you to move on if it is a clean break without ties...His approach might not be the best approach, but in heartbreak moments like that, there isn't really an easy and painless exit...He has sex with you because he is still sexually attracted to you...But now that you know, it is up to you if you want to confront the situation calmly so you can rationally move forward or let your anger eat you alive...

Just say, "Why are you selling your stuff?" Are you planning to move out? Why?..
Don't just put his things in the yard. If you're grown-up enough to live together, then you are grown up enough to have a real conversation. And you can tell him how disappointed you are that he didn't have the balls to tell you himself...

No...Bring up why he is selling his things...I understand it is annoying and it is your apartment and everything, but if he is moving out anyways why do you have to do it now?..And you are upset he is lying, but you are lying to him as well...You want to kick him out and haven't told him...You knwo he is moving but will not explain how and so my estimate is he is unaware of that too...And the sex thing, to be fair you had sex with him knowing what you knwo and so you shoudl not really be too mad...Just bring up everything you knwo and you will be able to figure it out from there...