As far as I'm concerned, the physical & psychological aspects of sex are inseparable, but are also on a continuum like the Kinsey scale. So sometimes getting fucked is mostly physical, I just want the relieve a bad case of horny. Other times it's mostly psychological, I need to feel needed, or need to be get out of my head as only getting fucked can do, or I need to dominate my top from the bottom. And then there's the middle of the spread, where the aspects are more balanced yet still fluid, waxing to the others wane, the waning in turn. And that's just my OWN physical/psychological dynamic; there's another half to the equation, the internal dynamic of the guy I'm with and finally, how well in synch we are.