When I arrive to my partner's(dx) place before we need to go to somewhere at a certain time, sometimes my partner will be running late and get incredibly stressed out because of it, and in turn, if I make a mistake in helping them get ready, he will feel insulted and get frustrated with me.

For example, I get to his place ASAP for his close friend's surprise birthday party. (I should have called him as soon as I got off work to check in to see if he was ready, I never learn lol). He's still not dressed playing on the PC with his friend when we need to leave in 20 minutes (he set an alarm that never went off), so he takes a shower, gets dressed, and then I find out he doesn't have a gift for his friend yet, but he decides to jokingly wrap something he gave his friend last year that his friend never took home.

So he asks me to help tape parts of the gift since it's an awkward shape, and I fumble with the dispenser because it's circular and opens up and I pull it the wrong way. He tells me the correct way to do it, and I fumble again.

This makes him upset, and he says he feels disrespected because he's in a massive hurry and he can't even trust me to perform a simple task. Honestly, in these situations, I feel really self conscious and get clumsy because I know he is going to be critical of me.

I get defensive and unfortunately blurt out "I'm not trying to disrespect you!" and of course he says he knows that, but he feels like I don't listen to what he says. Me not listening because I made a mistake is something he says a lot, and I told him I am just doing my best, and I will buy bags with tissue paper so he doesn't have to worry about wrapping anything at the last minute. He took my suggestion as sarcasm, but I was being serious because I want to avoid being stressed out. I said I was trying to be helpful, and he acknowledged that.

What's a better way to respond in this situation? I feel like I didn't reach him emotionally much and I just triggered a bunch of trust issues out of what feels like nothing to me.