In the last strip's commentary I talked about how Lillian made a (more or less) conscious decision to share some of her love with Roomie.

Roomie, on the other hand, is genuinely surprised. 

That's because at one point in time, after knowing Lillian a little better, after truly connecting with her on at least an honest friendship level, Roomie (very unconsciously so) decided that Lillian would never be interested in her/girls/anyone, really. For Roomie, Lillian was off limits. Didn't stop her from continuing her flirts and jokes around her of course. It was just Roomie's way to remain playful, it was her kind of humor and fun. 

But if she went a little deeper within herself, she'd have found that she had created a sort of barrier between her and LT. Something that stopped her from wanting something of Lillian that Lillian may have not being able to give. A protection of some sort. 

And at that moment, when Lillian kisses her, fully, that's when Roomie's barrier starts breaking. 

--> This is a rerun of the finished webcomic Go Get a Roomie! You can find these two strips in the old archive >here<!