This is the point where Ryan has faced the hardest part of coming out of your shell, which is the discomfort of change.
There is a part of him which his father planted that wants to be vindictive and give into his insecurities and assumptions. With the positive changes Ryan has made by demonstrating who he is to others comes with a feeling of fear toward the freedom he is gaining. Now the seeded defaults in his mind are trying to sabotage his new and strengthened relationships and cut off a positive attitude toward the world. He is trying to repel everyone and send himself back to the dark corner.
But what he has built with others, between others, and demonstrated from within himself is too powerful for anyone to turn a blind eye to. Lucille knew where to find him when he snuck out on a rainy evening, leaving his sister to panic. She's holding him there, not just as his girlfriend, but as an admiring companion who wont stand and watch their inspiration die.
Soaking in the vicious rain by the tree the two got to know each other under, Lucille will brave the weather and even Ryan's hurtful attitude if it means he will just sit with her and tell her what's going through his mind.
If you're a fan of The Boondocks, you probably know what song, scene, and episode inspired this XD