Sassy! Kate Hudson uses revealing snaps to make Nick Jonas jealous

What's the key to keeping your toyboy in check? A very pert derrière according to Miss Kate Hudson. 

While Nick Jonas and Kate's romance was supposed to be a casual fling it seems that the pair have taken their relationship well into winter as they were snapped together on a ski trip earlier this month. 

However, things were not always simple between the on-again, off-again couple.

According to US Weekly, a source revealed that Nick had made the decision to end the fling in November but it would seem that Kate had a cunning plan. 

That very month, Kate's stylist Sophie Lopez took to her Instagram to share a Polaroid snap of Kate in the tub. 

The 36-year-old actress even posted a cheeky comment on the pic saying: "Omg! You are so fired! #Fabletics."  

But if this source is to be believed, Sophie was told by Kate to post this in order to show the 23-year-old singer exactly what he is missing. 

And if all this is true, then it would seem that the plan has most definitely worked as the handsome due seem to be still together. 

The pair were spotted hanging out over the summer though they have remained tightlipped about any romantic relationship. 

Kate has two children from previous marriages to Muse frontman, Matthew Bellamy and lead singer of rock group the Black Crowes, Chris Robinson.