ついでだから

expression

might as well; since I'm at it

Used when taking advantage of an opportunity or doing something extra while already engaged in a related action. Often implies a casual, spontaneous decision.

• スーパーに行いくなら、ついでだから郵ゆう便びん局きょくにも寄よってきて。

  If you're going to the supermarket, you might as well stop by the post office too.

• ついでだから、ついでにこれもお願ねがいしていい？

  Since you're at it, could I ask you to do this as well?