Despite it being 'Father's Day', Raiden hasn't quite disappeared yet. He still has to thank Snake first. "Hey... Thanks for being a great Uncle." It's a bit awkward but he means well.
Snake turns to look at Raiden, realizing how difficult this day should be for him- considering everything he's gone through and yet... he took this opportunity to thank him for the things he has done, in the other's timeline and maybe on his own.
"..Don't worry about it. did the best I could." their relationship was odd to say the least, but snake did always see Jack as found family- as a mentee, and sometimes as a kid under his responsibility.
"You just keep doing what you do, Raiden- but never forget what the important things are. take some time to live, for once in a while."
