Hi there. I'm pretty sure I read this at least 5 years ago, around when ShoujoMagic was still active. I thought it was scanlated by Entropy but after looking through their titles, it seems not... Or maybe I'm blind and completely missed it. Here's what I recall:

A teenage girl's beautiful mother got remarried to another man. Then the mother dies. The man takes it upon himself to care for the daughter, but she develops feelings for the man. I think he pushes her away out of his love for the mother, and because it'd be a taboo to reciprocate the daughter's feelings. I think she might have been sleazy/gotten around due to this? It's a bit dramatic and I recall it having sort of a Deep Love vibe, probably not to that extent.

I can't remember the ending, but I think it was a happy one. He finally embraces his feelings and confronts her about it, or something.

Any help would be very appreciated! Thanks for your time.

Edit: It may have been one of ShoujoMagic's releases then, but I do think it was released at least 7-9 years ago...

Could it be Lovesick?
She didn't really become bad though.

Chinese Translator Accepting translation requests if the manga interests me!

Chiisai Hitsuji wa Yume wo Miru

Is that it??

I believe it was Lovesick, however I'm really interested in reading Chiisai . . . as well. Surprised I haven't yet since I've read the mangaka's other works.

Thank you very much for the help! 🙂

Edit: It turns it out was actually Forbidden Phrase, also scanlated by ShoujoMagic!