もののついで
Meanings
1
while you're at it; take the opportunity to
usually written using kana alone
Used when doing something as a natural extension of another action, often with a sense of convenience. Frequently appears in the pattern 〜のついでに or 〜ついでに. The expression 物のついで is a set phrase meaning 'since you're already doing one thing, you might as well do another.'
See also: ことのついで
If you're going shopping, stop by the post office while you're at it.
Since I started cleaning, I'll wipe the windows while I'm at it.