Don't mind my first reply, (what was I thinking? Really. ^^;), Changmin's family rejected him because he is homosexual (or some other reasons you like more) and Jaejoong comfort Min and kiss him for the first time.
In the last line, Min wants to believe he closes his eyes because he is still sad and not because he loves Jaejoong.

There. I think it's clearer?

Thanks a lot for your comment. ^^