What jumper can go with a boys polo t-shirt?

[SpotOfWeather]

So this is my boy's favourite t-shirt. When it's a bit chilly, what jumper could it go with nicely?

Plain navy v neck? Not exciting, but...

Maybe... I'm not a big fan of this t-shirt to start with! But he grew to love it so much that I'm tempted to 'complete the look'. Navy V neck could work.

Or a sleeveless cricket v neck pullover to go full preppie style 😄