Disciplining my son

Seriously I'm was so frustrated I was on the verge of tears all night. My son just turned three and has a friend (one of my high school friends kids) and he had his 2nd birthday party last night. My son is VERY rambunctious and I do my best to make sure he respects others and has manners. He got really excited about the party and we spent the week talking about how it was his friends party and not his.. Of course at the party Oliver wanted to sit next to him while singing happy birthday and even sang to him twice. I reminded him to let his friend blow out his candles and to simmer down. Then we get to the presents and Oliver is front and center wanting to see everything and offering to help his friend open his presents. He was jumping up and down and getting out of control so I reminded him once again to back off, sit down and just watch. This random old man nudged my arm and said 'oh leave him alone, he's just having fun!' 😑 I seriously had to hold back the tears.. I was so mad. Why am I not allowed to make my child behave?! Why am I being shamed for holding my child to a certain standard? He's three.. I get it. But when half of the moms up there are telling him to sit down and the other half are telling him it's okay.. Wtf am I supposed to do?! I want my son to learn to respect others. I don't think there's anything wrong with that. Am I wrong? Grr.