sniggering silently down my sleeve. when you don't want to lol because you are simply not that sort of person. yet 'hahahahaha' doen't quite cut it and writing 'i am laughing' seems sterile.

Silently Sniggering Down My Sleeve.

The slightly more adult and accurate version of "lol" as everyone knows that when someone is laughing out loud, no real noise is being made.