Yes and no. If your friend dated someone AND said friend is not okay with you dating him, then he's off limits. But if your friend is okay with that you can totally date him. But yeah, you should make sure how your friend feels about it.
I really think Maya did have feelings for him (always have) and she felt bad because her friend was saying they weren't together but still liked each other... However I can't stand what happened in the third season with all about that triangle.