I wonder if YJT by now is getting hate mails from the SL's fans hahaha..YJT performance in episode 18 was excellent though..very gut wrenching but superb.
I was mad at Chulsoo yesterday but not so much anymore. I actually feel sorry for him for not knowing how to love. How his terrible childhood has affected him ability to love and be loved. I like one comment posted by Jusash in Soompi forum. So I am quoting his interpretation as follows:.

" As for all the Chul Soo comments .... while I am exasperated with him too - to be fair to the guy - it can't be that easy on the dude dealing with Ma-ri either. (and life though painful without Ma-ri, is also uneventfully a lot more peaceful it seems).

Even before Ma-ri had made her official engagement announcement (made in really bad timing too - after CS had spent all day and night in the cold waiting for someone who didn't show up. imagine dealing with this news on top of the rejection) ......

There was also that previous episode with Seo Woo Jin - where Ma-ri just chose to live with the guy, and keep Chul-Soo in the dark about what was going on. Imagine Chul-Soo's compounded insecurity.

What with one thing after another, one guy popping up after another ....
You can imagine how conflicted conservative Chul Soo must feel - he, the virgin in matters emotional (sorry lady but Eun Young doesn't count or figure at all in my books re: Chul Soo + love).

Chul Soo is even a virgin in the art of kissing .... remember Ma-ri teasing him at the table the day after her 'I can fake it' kiss and asking him if it was his first (and CS blushing and changing the subject?)

Ma-ri's the more experienced one.
So CS must find it hard to deal with the roller-coaster parade of guys in her life ... especially since Ma-ri does sometimes send mixed signals about the guys in her life to him. (remember Chul Soo's conservative comment made at the rooming hostel about how she could just sleep over in a guy - Lee Woo Jin's - house, just like that?)

Those two really need to communicate!"