Hi Culture,
Yes you are right.
I also remember Dev (Disha's real father) telling DK that when bade shaab (Dhruv Seghal) was alive he never let his wife get dishonoured in any way. This was said when DK and Sanya were waiting in Kanaka house for Disha to get ready for the photoshoot.
Here is the part from the update:
"DK is waiting for Disha to join Sanya and him and leave for the shoot. Just then Dev comes and in a very mousy voice tells DK that what he is doing to Disha is a sin and that after all Disha is the Bahu of Sehgal Khandaan. Dk just keeps looking at Dev without any expression. Dev then says that DK is like his son and Disha is his wife, it is DK's duty to uphold Disha's honor and instead he is making a spectacle out of it. DK replies very cooly that he is very well aware that Disha is his wife and what transpires b/w them is entirely his concern. He says that he is noticing Dev's concern & attachment for Disha, he asks Dev very sarcastically that is Disha his daughter, that he is being so concerned. Dev feels very bad but still gathers guts and says that whenever he looks at Disha, he is reminded of DK's mother (at which DK's expression gets very emotional and nostalgic) and as long as the senior Mr. Sehgal was alive, he never let his wife's get dishonoured in any way (actually the line in hindi was "Jab tak Bade Malik zinda the, unhone kabhi bhi aapki Maa ke sar se unka aanchal bhi sarakne nahin diya). As soon as his father's name is mentioned, DK gets the same cold, anguished expression on his face and gives a tight slap to Dev and says in a very tight voice that he does not want to hear his father being mentioned in this house. Sanya who is standing nearby gets petrified at seeing DK temper and keeps standing where she is. Dev is humiliated and gets tears in his eyes, DK turns his back and closes his eyes shut tightly as if to avoid some bad memories."
So this indicates Druv and Sumitra were married.
Druv could have divorced Sumitra and married Gargi as his mother wished.