As part of an Ex on the Beach press event, keen singer Megan was out in central London to sing for the crowds.
But Lacey didn't seem that impressed…
While others took photos and cheered Megan on, fellow EOTB star Lacey decided to drop a £50 note into Megan's collection on which she'd scribbled the words: "I always donate to charity."
Lacey later retweeted several fans who congratulated her on the gesture, and replied to one: "Karma's a bitch."
Fans of EOTB will know there's no love lost between Megan and Lacey. Megan made her debut on series four this week, alongside then-boyfriend Jordan Davies, and immediately took a dislike to Lacey as she'd once slept with Jordan before he met Megan.
There were plenty of insults thrown Lacey's way by an angry Megan, including saying: "When I saw that motherf**ker's face, I thought, f**k me, Jordan has been scraping the barrel. She's a four out of ten, mate."
Lacey decided not to respond and instead said she'd put her guard up.
EOTB continues Tuesday at 10pm on MTV.