I like how Senpai is not running away this time when Nagatoro's friends barge in for some "sparring". It shows that he's getting more used to these scenarios, not letting himself succumb to the teasing and pranks that the friends would put him through (at least not initially).
Also when Nagatoro says "That was so gross, I just had to smile!" I feel like that's her go to excuse for whenever she finds herself having a good time with Senpai. It's sweet.