New Delhi, March 30 -- : Salman Khan's sister Arpita Khan and her husband, actor Aayush Sharma, on Monday celebrated the fourth birthday of their son Ahil Sharma.

Taking to Instagram, Aayush posted several pictures of the birthday boy right from his birth and penned down a heartfelt note.

"It's been 4 years since you've come into our lives and since then you've only made us smile and bring happiness into our lives. I haven't taught you a lot but you taught me the meaning of selfless love," he wrote in the caption.

"Thank you for making me a father Happy Birthday my little Avenger .. too many more priceless hugs and fictional stories @arpitakhansharma," he added.

The couple who got married in the year 2014 are parents to a four-year-old ...