SSSS = Sorta Second Sock Syndrome

This always happens - after the heel of the second sock, I always get bored and start itching to cast on a new, more complicated sock. This only really happens with plain socks - ribbed, stockingette, anything where I don't have to think really. Mr. Loopy has big feet. And it feels like miles and miles of boring knitting and I want to knit something more complicated. I'm torn between taking his socks off the needles and casting on for some lace socks for Mom (her Christmas gift) or continuing. I just don't know.