Pornwarp
You're on the PC, you're doing something constructive, but your attention wanders, you start to look at dodgy websites, and before you know it it's 4 hours later, you've been looking at naughty ladies for all that time, you've been stuck in a PORNWARP!!!
Yeah, I was going to get that report done last night, but I got stuck in a pornwarp, and before i knew it it was time for bed....