Should I have let my 25 year old son stay with me?

Two months ago I kicked my 25 year old son out of my home. There is nothing wrong with him he is very capable of working. In 2009 I let him move in with me because he lost his job in NC, I told him there werent many jobs in Va. either but I let him move in. For 2 years he would not look for work he would just sit around I even got him a job and he would not do what the employer needed him to do. Finally I had enough I kicked him out in April 2011 I told him he was not trying and I could not take care of him anymore. I knew he could go live with his sister so that is where he went. I did tell him at that point if he had no where to go I may have let him stay but his sister said he could live with her so I did kick him out. He told me when he left I would never see him again. Well June 24 he comes to my home and ask to move back in? He said he could not live with his sister anymore and had no where to go. I said NO you cannot come back here. He asked just for one night? I said NO. It broke my heart but I cannot go back to him being there and doing nothing. HIs father died in 2006 so I am his only parent. My heart is breaking so much it was so hard to say NO but I feel he needs to get out and try and make something out of his life. Should I let him stay with me forever!!