His love for you is not sexual. He wants your relationship to be platonic.
It means he either still likes you or hes playing with you...
If a ex is horrible and mean to you it means she either knows someone who likes you and sh doesn't like it, or she likes you. No it is not
The ex is trying not to hurt your feelings by being "nice". The ex still likes you as friends but no longer romantically.
tell him
It sounds like he's hoping his ex will take him back but he's keeping you around just in case she doesn't. This is not fair to you, in my opinion.
You can if the sister says yes but I don't recommend it. It might cause some friction.
Personally, I think it means that either he was using you for some reason or he realized sometime in your relationship that he no longer had feelings for you.
maybe he still likes you or you will forever have some sort of connection
You tell your best friend that your ex likes her and see what she says, explain to her how you would feel if they went out and if you were okay if they did. but also, do not ever get in the way of what they could share.
it means he has no continuing feelings for his ex.
talk to him about it
If your ex likes you so much you should ask him one last time if he likes you, and ask him which girl he might want to go out with.