Most Helpful Girls
When one of them aren’t happy being with their partner and if the person doesn’t have feelings for their partner. That’s when the relationship should end. It wouldn’t be fair on the other partner if they stayed in a relationship with their partner.
When the both of you or one of you isn't feel the same anymore? It is quite hard to remain in a relationship wherein there are just empty feelings and sadness.
Most Helpful Guys
There's never a "good" time, but some thoughts would be:
Don't wait until you resent her presence
If you have ANY feelings for her it's not too late.
If you realise something's wrong, talk about it - to her, not your drinking/poker buddies.
From your question though, you already have. You just didn't tell her yet.
The moment you start to dread hanging out with the person and/or start thinking of different excuses why you can't hang out.
Has always been my barometer