I have heard 2 definitions of this:
1)
Lolomgwtfbbq -
lolomgwtf (you know this) bitch be quiet. Ifsomeone says a completely
stupid thing, or something that is rediculously funny.
2) Lolomgwtfbbq - Something that is a filler and/or word describing confusion.
1) N00b:
You know how i know your gay? Cuz you are gay and like loads of girls.
Me: lolomgwtfbbq
2) n00b:
durka durka durka muhammed jihad
me: lolomgwtfbbq - i dunt speak pakeh