Yep, he does, so that's why he won't give Daniel the second letter from her. And his mother is encouraging him to go after Lily too

Here's some of the transcript:
** As Devon works on his homework - Yolanda is checking out clothes - how does this look? Devon - that's nice. Yolanda - no, I'm going with a skirt - this isn't right for the office. Devon - I keep thinking about Lily - it was cool getting to see her. Yolanda - you miss her - huh? Devon - I wish she could have come back with us. Yolanda - maybe she can soon - she broke up with her boyfriend - right? Devon - how do you know that? Yolanda - Neil mentioned it - they sent her away to keep them apart - I'd say it worked. Devon - maybe it was best that she didn't come home - those two would just get back together - that guy is bad for her - I don't understand why she can't see that. Yolanda - you miss that girl a lot. Devon - yeah - I've got a thing for her and it's not like she's my sister either - I probably shouldn't have said that. Yolanda - I'm glad you did. Devon - do you think it's weird? Yolanda - that you have feelings for Lily? Devon - yeah, I've never said that to anyone before. Yolanda - there is nothing wrong with that - you aren't related - you didn't grow up together. Devon - but I can't ask her out when we live in the same house. Yolanda - I may have my own place soon - when I do you can live with me - then asking her out won't be a problem.OMG!