The Obsession (2006 TV movie)
starring Daphne Zuniga, Elise Gatien, Sebastian Spence
A ballet teacher's obsession with a young student leads him to date the girl's unaware mother in order to get closer to the object of his twisted affection. Deborah Matthews' divorce from her husband has just been finalized. Jason has since moved away to work on an often communication inaccessible research ship. That fact and the divorce itself does not sit well with their 16-year-old daughter, aspiring ballerina Erika, who blames her mother for the problems due to her being a workaholic and not forgiving Jason for the denied indiscretion. To make matters worse, Erika's long-time ballet coach has quit before her important audition for the Ballet America summer program. Luckily, the ballet school is able to fill immediately Mr. Capas' job by a young man named Reed Halton, who believes he can help Erika prepare for her audition. It seems too good to be true. And, it is.
The second one sounds very familiar. I'm positive that I've seen it. However, it might take awhile to dredge it up from my memories.