The pair are said to be in a relationship after he began managing her girlband Vida, according to The Sun.
Williams had invited Jane to Antigua for JLS's holiday, where she joined their close friends and JB Gill's partner Chloe Tangney.
A source said: "It has been nice for Oritsé and Amy to spend some time together.
"Oritsé is one of the hardest-working members of the group, plus he spends a lot of time looking after his mum, so it has been nice for him to relax for a bit.
"They get on really well and are relaxed in each other's company. It might be a big group holiday but they've still managed to find a bit of time to themselves."
JLS recently hinted that their new single will be released in the near future.
Watch the music video for JLS's 'She Makes Me Wanna' below: