I don't know

When communicating things in your relationship, I think it is always best to find the most compassionate way to bring something up, especially if you are afraid to bring things up. "Hey, is something the matter? I feel like [insert problem here] and it makes me think that you haven't been feeling well."

The time you bring a problem up can effect if it becomes uncomfterble or a good time to comunicate,  avoiding a time were perhaps they will sleep derecktly afther. 
Oddly enough I have found that bringing something up when it seems the most out of place is ofthen the best for clear comunication, like afther having had a meal or wile on a walk.

break up w em dude ur too cool to deal w ts