Newly engaged Pippa Middleton couldn't stop smiling

James Matthews, 40, popped the question to Pippa Middleton, 32.

She stepped out for a third day flashing the new diamond rock.

Pippa will one day become Lady Glen Affric thanks to her fiance.

His father owns a 10,000-acre Scottish estate near Loch Ness.

Pics: Getty Images

Pippa flashes her £200k engagement ring 

James Matthews, 40, popped the question to Pippa Middleton, 32. (AP)

She stepped out flashing the new diamond rock. (AP)

The art deco inspired ring is estimated to have cost £200,000. (Getty Images)

(Getty Images)

(Getty Images)

(AP)

(Getty Images)

(Getty Images)