Been there, done that; it didn't work very well at all for me because I was so busy trying to separate what I told each and ended up divided and worried (what one would think about the other). I finally told my main professional and she asked me to quit the other and I did and was glad I did it that way.

If you really like the student and they want to work with you; tell your professional and terminate with that T; get your whole heart one place or the other.