Ore no Aoharu wa Susumanai

Subaru and Jinnai's first springtime bore fruit in the form of them becoming lovers! However, Jinnai hasn't tried doing anything further ever since they first touched each other at Subaru's house. Subaru now found himself worrying about this especially since the shoujo mangas that he makes his bible don't show anything beyond kissing between lovers...
Then one day, the two got into the hottest mood they've ever been in before but then Subaru, in his nervousness, bluntly said to Jinnai with a smile, "If it's you, I'm sure you can do it smoothly and well, right?"