I can't resist his smell

So, I have this classmate with bad feet smell, I swear to god I can't support anymore, neither sit next to him, so stinky in a way I can't breath any more. Any suggestion on how can I tell him the truth without hurting his feelings ?

Edit: I mean can't stand it , Idk why he always sits next to me , besides I try my best to avoid him :(

Edit 2 : There is an another classmate , who got the same issue , he puts always the same shoes .