...I do understand.I'm sure that she is afraid that you will be taken away by Reimu, Mistress.
"Taken" as in Remilia's feelings/love/attention will all go to Reimu and Flandre will be left alone/unloved/ignoredBe-beloved...!Please try to understand the Young Mistress' feelings...Flan's RoomMy, you certainly are the Young Mistress' beloved, Mistress.