I know exactly how you feel. I have a close friend who is more like a brother to me, but it absolutely pains me to watch him grill and know I have to eat it but I suck it up and keep my mouth shut because all he has done for me is easily worth having to endure that a few times a year. It's funny cause he cooks 1/4 pound burger pattys for about 20 minutes and flips them every minute or so. He also douses everything with BBQ sauce, and starts basting immediately when he puts it on the grill.
On the flipside, I am happy to say that my son-in-law has taken an interest in learning how to grill and whenever he does he asks me to come over and coach him. He's been really good about soaking up any information I pass his way and he's been turning out some pretty good cooks for someone of his experience level. Saturday was his birthday & Sunday father's day and I normally would have cooked but I still can't be on my feet for long periods of time so he decided to throw some ribeyes, burgers, & sausage on the grill Saturday night to celebrate both. I occasionally stepped outside to take a peek but he pretty much flew solo and did a very good job. Steaks & sausages were cooked almost perfectly. Burgers were a little on the dry side, but it was just from him wanting to make sure they were cooked all the way through. We enjoyed everything though and it was nice to enjoy someone else's grilling for a change!
Edit: BTW, I just gave him my Weber one touch gold that i've only used twice in the last 2.5 years since getting my BGE so he would have something good to learn on. He's absolutely thrilled.