There is a joke in our language. Father and his son are sitting and talking. Father is complaining that his son is stupid: he knocks the table and says "you have nothing in your head just like this". The son is answering: " dad, someone is knocking the door!". And dad: "sit down, son, I'll open the door!". The end. :) The knocking sound is similar to tuk-tuk, so I differ it from the fat one.
just a protip here. you don't go round calling your partner a lover. it's slightly disrespectful.
Eng. equivalent "My better half"?
애인 is just someone of your affection (intimate but no physical relationship). 연인 has a more serious meaning (prob. closer to "lovers").
So describing 애인 as significant other seems a bit of an exaggeration, not?
It is really just a flowery way of describing 남/여자친구, is it not?
Significant other/ significant lover is too cumbersome. Partner is too politically correct and neutral. Keep it simple, choose boyfriend or girlfriend, add the missing context you should know. My boyfriend is smart or my girlfriend is smart are as equally correct as all the other translations.