I have come very close, where he only needed to do a single touch to get me off.
I was once with a guy who could get off by performing oral sex on a girl. It didn't happen each and every time, but it was awesome when it did!
I love getting my partner off and it definitely heightens my arousal but to actually have an orgasm I need at least a little physical stimulation. I have found that after spending some time just focused on pleasing my partner means that it's incredibly easy for me to cum and doesn't take hardly any effort.
I haven't, but I'm a guy. We have coordinated several climaxes together but it wasn't necessarily because my wife was getting off when I was. She gets very excited by me getting off so it may be true for her that she's gotten off when I do.
I don't think I can get off just by looking but yeah watching your partner is a major turn-on that can help you orgasm yourself.
I believe you, and I have experienced something similar. I do require some stimulation, but I've cum while giving head several times.
A previous girlfriend came while giving me a blowjob. She was able to stimulate her clit by putting her legs together and moving a certain way. I could feel when she came, and it made me cum almost immediately.