Example. I receive a message on whatsapp, she then says, "oh, it must be some of your other girlfriends". Or I ask if some thing in my bathroom is hers (I love with my mom), and she says "oh no... It must be from some of your other girlfriends".

I usually just laugh about it. I don't think it's irony, but I can't decode why she says this so much. My value to her is very big I think, but in these cases I don't have so sure. My phone has a password and hers has not, maybe it's a comfort test?

Help me figure this out