Just had to check if this was the KJ's only section. So my reply will have to be slightly more cryptic - I get asked to sing a lot of duets and I have a few singers who opt to sing the same songs on a regular basis.
I can sing a song about four times before I get bored of it. Some 'long' and 'popular' duets are just on the edge of my vocal range
and some shorter duets that come in original and reggae flavour I sometimes find myself singing twice in a night.
Luckily I like the people I sing them with.