"How many bags to check?"
"Two"
<tappity tap>
"Please place the first bag on the belt"
etc, usual process continues.

If asked "are these your bags?"
"Yes"
"Did you pack them yourself?"
"I packed one, my husband packed the other".
or as appropriate.

I'm not quite seeing the problem here.

All sorts of other things happen if you say "no, these are not my bags at all, I'm just checking them in someone else", but that's not the case here.