Think of yourself as a prostitute, someone who fucks for money with no expectations of pleasure; sometimes for ambition and sometimes, just for the fuck.
You feel nothing. There is no involvement of the heart or the mind. You just spread your legs, lie down and let it suck your soul piece by piece.
All the while, playing your favourite song in your head or thinking about the recent book you read or the last good fuck you had. You replay all this over and over and forget where you are. You live in your head while your body goes through the motions.
It’s a means to an end. It means nothing. It’s just a fuck. Just business. Nothing personal about it.