Board Thread:General Discussion/@comment-25115701-20140629045455/@comment-14250-20141016205149

She may feel more awkward around Donnie because she thinks he has more delicate feelings than Casey and she may care more about Don's feelings than Casey's. Casey has more experience in the human world and can be flirted with a little without his hopes getting up too much. Don is a delicate recluse so April doesn't want to mess with her fragile heart unless she knows for sure she wants to be with him. Another reason is, well, he's a mutant turtle, some feelings of awkwardness are expected.