Spam is the use of electronic messaging systems (including most broadcast media, digital delivery systems) to send unsolicited bulk messages indiscriminately.
IE: forcing messages onto someone without considering.
The term 'spamming' has been overused for a long time. Especially when the receiver
himself isn't considering the messenger's intentions, the term is often used very loosely.
You weren't spamming him, he simply failed at expressing himself correctly in order to tell you he was getting bored with the conversation.
Or he could just be polite and take it like a mature person would.