Nick Jonas' most embarrassing red carpet moment was when he got a "no apparent reason boner" at the Young Hollywood Awards.

As he took the obligatory walk down the red carpet to pose for photos and meet fans, Nick felt a rapid rising in his penis and panicked as his pants began bulge and placed his hands over his swollen member.

Recalling the red carpet experience on 'The Tonight Show Starring Jimmy Fallon', he revealed: "I've never told this story, for good reason probably ... Out of nowhere, I get a NARB. All men get a NARB from time to time. A NARB is a Non Apparent Reason Boner."

The whole day of July 27 - when the Young Hollywood Awards - was a nightmare for Nick.

When the 'Close' singer woke he was suffering the after-effects of accepting a cannabis lollipop from one of his friends' wives during a night out to celebrate the new music he had been recording for his second solo album 'Nick Jonas' - which came out in November 2014.

Unlike a normal hangover, Nick experienced some odd side-effects, including "hearing voices" in the shower and he quickly had to find something that would shake him out of his post-partying slump and get him ready for the awards.

However, the former Jonas Brothers star doesn't know if the marijuana candy was the cause of his erection.

He said: "(When I was offered the lollipop) I was like, 'Yeah, sure, why not? I never do this - never happens.' I enjoyed the night. Felt great. Went to bed feeling fine. Woke up the next day ... everything's in slow motion. I'm hearing these voices (in the shower). It's horrible, so I call down to my girlfriend who's in the kitchen. 'Babe, I need some bread, I need some coffee. Something!' So I'm panicking. I go back to bed and wake up a couple of hours later."

But nothing worked and when it came to him handing over a prize to Ansel Elgort he fell apart on stage, although, luckily, his erection had dissipated.

He recalled: "So I'm presenting an award and Ansel Elgort's just won, he's really tall and I'm not. I get up and I stand on stage for probably 20 seconds without saying a word, just looking around. I pick up the microphone and I try and say a joke that wasn't in the script because I thought it was just going to be amazing. I'm like, 'I would love to have the same problem as Ansel but I'm short ... err.' I walked off stage, I looked at my manager, I was like, 'Do you think anybody knew?' "