euphemistic mouthful

Reader's Digest Dec/Jan号の記事からの引用です。
You're over 30 and have been with the same guy for three years, but you are not married. Calling him your boyfriend seems childish. Significant other is a euphemistic mouthful. Partner sounds as if you're in business together, and lover seems to steamy. How do you introduce him?
英語が母国語の人が感じる "boyfriend"、"significant other"、"partner" のニュアンスが分かる記事で興味が湧きます。
"mouthful" の意味を辞書で確認します。
・Oxford English Dictionary: A long or complicated word or phrase that is difficult to say.: “Galinsoga” was too much of a mouthful for most nonbotanists.
・Collins Dictionary: If you describe a long word or phrase as a mouthful, you mean that it is difficult to say.: It's called the Pan-Caribbean Disaster Preparedness and Prevention Project, which is quite a mouthful.
・Cambridge English Dictionary: a word or phrase that is difficult to pronounce or that has a lot of syllables: I've always called myself Henny because it's less of a mouthful than Henrietta.
"significant other" なんて覚えるとつい使いたい言葉ですが、英語が第二言語の我々は聞いて分かれば良く、やたらに使わない方が良いのでしょうね。
ところで、質問に対する適切な紹介法は次の通りでした。
Simple. Introduce the person by name.