Stuff i read up based on statistics in the change of behaviour.

1. she really just wans a shoulder, someone who will listen, someone to talk to. she not just meat for u to have sex 24/7. Sex isnt everything, communicate more. Feeling loved it better than just having orgasms.

2. there's a 3rd party that she did not tell you about. and now she doesn't know wat to do. might have found new sex excitements with some1 else and lost them with u. if so, u'll have to face it.

3. something happened, at her workplace or her family something.

Just talk to her man. And listen. NEVER cut her off. NEVER make her feel defensive, else she'll lock herself in and she wont tell u wats wrong. Then u'll need all the luck in the world.