Umm... how long does it take for an average guy to cum? My boyfriend literally cummed in 30 secs without even touching my vaginal area... what happened?

All he did was finger me and then he came I dont understand and then he got all embarrassed I didnt even finish it was 30 secs of like nothing and then it got really awkward and I started to feel naseous... and he walked away....

Did I do something wrong?... Did I do something right?.. What did I do?!?