Men have long bemoaned the idea that women can have multiple orgasms, but men can’t. Men, after all, have to deal with the frustrating refractory period—after an orgasm, their penises stay limp no matter how much they try to coax them into action. Their energy levels are depleted, anyway, and they often just want to sleep. But men actually can have multiple orgasms—as long as they separate their orgasm from the physiological experience of ejaculation. Orgasm and ejaculation often occur in tandem for men, which leads a lot of men to thinking they’re the same process. But they’re not. It is possible to separate the experience of orgasming from the experience of ejaculating. Learning how to separate orgasm from ejaculation takes a lot of effort, determination, time, and practice. It’s not something you’re going to learn overnight. For some men, it may not be worth it. You may also find that focusing so heavily on trying to orgasm in a very specific way takes the fun out of orgasm. But fortunately, many of the techniques you need to use to learn how to have an orgasm separate from ejaculation are techniques that are beneficial in and of themselves.
If neither of you hurt each other and both of you enjoyed yourself then you didn't do it wrong. When I read the part that said 5 minutes it almost made me laugh. I understand that sometimes with younger men everything is new and sensitive and they're really excited so they may ejaculate quickly after starting.
however at my age, 5 minutes is just getting him hard, it is usually between the 30-40 minute mark that he ejaculates. I wouldn't worry at all about 5 minutes, if it lasts more than 45 minutes then just give up and try again a different time -he could be too nervous or too tired and by then guarantee you'll be tired too!
If he is also 16, maybe his common sense was telling him that this was kind of new, difficult, or even embarrassing. You might try a hand job next time if there is a next time.