India, Nov. 3 -- Actor Hrithik Roshan (51) marked his girlfriend, actor-singer Saba Azad's 40th birthday with a heartfelt post on Instagram on Saturday. Sharing a series of candid photos and videos, he wrote in the caption, "From everything I reach for, dream of, and do, being a good partner to you is my all time favorite thing to do. Happy birthday my love (sic)." Saba responded with a short comment: "My heart". Hrithik's ex-wife Sussanne Khan also left a heartfelt wish, writing, "2nd pic classic. Happy birthday Saboo have a beautiful amazinggg year." His father Rakesh Roshan commented, "Saba birthday greetings & happiness always." Actors Dia Mirza Rekhi and Siddhant Chaturvedi also sent warm wishes. Hrithik and Saba celebrated four years of being together last month, with Hrithik sharing unseen photos and a note calling Saba his "constant source of calm". htc...