Amai Koe wa Saidai Volume de

Yuuta Mogami, a junior in his high school club, is a handsome and friendly guy. Every single day, he comes onto his senpai, Daichi Seto, who goes to a neighboring university, libidinously, saying, "I masturbated to senpai's voice" without giving up despite getting brushed off each time.

Even though Daichi should be fed up with Mogami, his direct "suki suki attack" throws him off his pace. In the end, when he sees Mogami chatting happily with his friends, he gets jealous...

(Source: Takeshobo, translated)