It’s a little bit awkward of a joke, but the premise is “I’ll love you as you get older” being contrasted against blue shirt’s callous behavior towards an old woman, showing that he might not be telling the truth.

https://en.wikipedia.org/wiki/Manosphere

https://www.eviemagazine.com/post/the-wall-women-have-expiration-date-dating-marriage

https://en.wikipedia.org/wiki/Sexual_objectification