Here is link
http://hi.krishnakosh.org/कृष्ण/महाभारत_विराट_पर्व_अध्याय_16_श्लोक_42-51
Yudhistar never ask draupadi to forgive kheechak but he was telling that wife never get angry at husband and by doing husband services wife go to heaven
He just said to draupadi that u don't understand situation right now
And yudhistar even tell to draupadi that one who insult u , gandharv ( as pandav disguise as gandharv) will kill them and will remove ur pain
No where yudhistar ask draupadi ask to forgive draupadi
That kshama word come from Mahabharata teller he told to king that why draupadi has not curse kheechak and Mahabharata teller start explaining importance of forgiveness