The London raised rapper (real name Ben Drew) had been performing at Shepherd's Bush Empire in the capital yesterday (29 August) and decided to head out to Groucho Club with his pals to celebrate, when he came across a man sleeping on the street and appeared to check if he was OK.
Spotted leaning down towards the man at first, Plan B was then seen handing him a £50 note before offering to help him up from the pavement and on to his feet.
The chart-topper was dressed smartly for his night out in light blue jeans, Vans trainers and a patterned, short-sleeve shirt.
Also out for the evening at Groucho Club was Laura Whitmore, who arrived at the venue with model Zara Martin and singer Diana Vickers.
Laura wore a funky skater dress with a leather jacket, while Diana opted for a red cropped top, leather shorts and trainers.
The girls had been to watch Plan B at his gig earlier that evening and were obviously keen to continue the fun with the man himself afterwards.
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Watch Plan B's video for his smash hit 'She Said' below.