I personally question the 'vanilla' tag on this one, as (IMHO) Tsutomi rather forcibly applied the vibrator to Asuka, despite her initial reluctance. If the artist was trying to convey the impression that "her mouth says no, but her body says yes", it didn't register like that with me. And even though for whatever reason it seems she can no longer satisfy herself without using toys, her (a-hem) boyfriend's reactions later appear to be more about his excitement at seeing her reactions, rather than helping her to enjoy the experience.
Of course, that's just me, and not necessarily the impression of anyone else. 🤔
I felt the exact same. I was gonna comment "His heart may be in the right place, but his dick isn't! When your girl says stop, you stop. Give her time to get used to new experiences."
Me: Let’s find out - in a sequel!