Corrupted Love - To those who want to argue this still applies to OP's request, keeping it vague if they choose to play so story is not spoiled.
Grandma's House kind of falls into the parameters a little bit with some of the LI's, there are others where it's open. It also flips what the OP asks as well where you play with the mother while keeping it quiet from the GF.
If it's just GF it does narrow it down quite a bit. If Jeffnews just means LI it opens it up to quite a bit more.