Suppose cac and I are lying in bed and we're snuggling and touching/caressing each other. I'll become aware that our physical contact has aroused cac, but my awareness of that even with the touching added still won't typically trigger arousal in me, if I am not feeling sexual. I might really be enjoying the closeness and physical touch and feeling validated by his response, but still not feel aroused. For me, I don't think it has that much to do with whether or not I intentionally caused his arousal or did anything specific to generate it. He could come at me with an arousal and I could be interested in having sex, but if I wasn't feeling sexual, I would have to make a conscious decision to change my mindset. My drive is just so variable.
I have noticed that I tend to feel more sexual in the morning than I do at night, and because of that I can get aroused much more easily in the morning. Not sure why that is. Maybe I'm getting a bit of testosterone in the morning? Or maybe it's just because I'm a morning person.