It is very arousing to hear the play-by-play of where the other cock is at in the process. I love giving out details of what I feel and where I feel it.
Very true. However, sometimes, no matter how hard you try, it's impossible to hold it back! Myself, I like cumming separately. That way I can enjoy my orgasm to its fullest without being distracted by my partner's orgasm, and vice versa. But sometimes it is nice to hit the peak together.