This could also go either way. Based on Tanaka's reaction ueno could be thinking that tanaka takes relationships seriously and thought of it as a prank or it could mean that he doesnt like ueno and shouldn't do that. But of course her plan backfired tremendously.
@bainhardt thanks for putting me in the end note. That's how I also confirmed that a volume 7 was coming out. I am so glad a new book Is coming out. Thank you for scanlating my favorite manga and I hope to see more work from you.