yes, they have and it's cleared at 1st epi.. JD paying money Anita since 1 year so obviously he'll not wait for Pankti's willingness, he has lust on her not love.. and at 1st epi JD celebrated 1st anniversary and said "tum hai pata hai na hum kis chis ki anniversary mana rahe hai"... also Pankti said she's sacred to die otherwise she'll free herself from this relationship long time back.. and I don't know u guys noticed or not but in 1st epi JD & Pankti car scene, JD go closed to her then blurred them and finished that scene so it means something happened between them.. even in last epi party scene JD's talk with her was very dirty and vulgar..
unfortenutly its is hinted that JD has a physical relationship with Pankti and that too since 1 year
she is actually sold to him