Blowjob time

Ok so I just gave a blowjob for the first time. He said I was really good and seemed to be enjoying himself lol. He was moaning and thrusting. However it took him a long time to cum. I know that people don’t usually do it till he cums. It took him around 20-30 mins idk was it that he just takes long or that I was bad. I even text him thinking maybe he didn’t wanna tell me in person and he still told me I was good so how long do guys usually last from blowjobs.