Johannes Saapar from Estonia

I found this photo in an antique store in Estonia. On the back of the photo it says in Estonian: Johannes Saapar (my uncle). 

Johannes Saapar is the older brother of Amelie Annimäe née Saapar and the nephew of August Saapar (click on the names to read my blogposts about them). 

As a matter of fact, Johannes can be found in the wedding photo of her sister Amelie. I believe he and his wife Helmi were the bestman and maid of honour at Amelie's wedding: 

Johannes Saapar was born on October 1st, 1899, in Kihlevere, Estonia, as the only son of farmer Jüri Saapar and Katta Kristiine née Klaasberg. He had three sisters: Amelia, Therese Lucine and Milde. I don’t know what Johannes did for a living. He might have been a farmer, like his father. He married Helmi Renata née Titwei on May 28th, 1928. The couple had two children: Silva Pruer née Saapar (1929-2021) and Ants Saapar (1935-1991). They both seemed to have had children of their own, so I’m hoping to make contact with their families and return the photo. 

I found one more photo of Johannes Saapar on Geni.com:

As well as one with his wife Helmi:

I wish I knew who the other young man in the photo was. So far I have found zero clues: