Puzzle 016: The Husband's Changes

ナゾ０１６　変わった夫
ある夫婦が海外旅行に出かけた。
１ヵ月後、帰宅した２人を見た隣人は
妻に対しては何も言わず、夫に対して
「ずいぶん見かけが変わりましたね！」
と、しきりに言った。
だが夫婦は出かけたときと服装も髪型
も体重も全く変わっていないという。
いったい誰の何が変わったのだろう？
ひらがな２文字で答えてほしい。

Google Translate
A couple went on an overseas trip. One month later, a neighbor saw two men went home to his wife without saying anything against her husband, "I changed my appearance a lot!" Said eagerly. Husband and wife but his weight has not changed at all when the hair and clothes and went out. Who will wonder what changed? Want to answer two hiragana characters.

Notes on Puzzle
A couple go travel abroad for a month. When they return their neighbor says, “You really look different!” However, their clothes, hair, and weight haven't changed, so what is the neighbor referring to? The answer is a two-hiragana word. I think there is an additional clue – the title of the puzzle is “The Husband's Changes” so you know the answer has to do with the guy. Once I realized that the answer was fairly straightforward.