A circle/group of friends, that write their names in a circle (typically on a poster board) and then write the names of at least two of the friends have hooked up with, using different colored line to show what happened between the people.
blue line: oral
green line: vaginal sex
red line: anal sex
Thus, OVA (Oral, Vaginal, Anal).
People can be added to the 'web', from both sexes, as long as two or more current people on the OVAWeb have hooked up with the person, whether it be oral, vaginal, or anally.
Basically, it's a graphical version of 'eskimo brothers'.
And the fun begins...
Dude! Wait a minute. You banged her last week?! I banged her three days ago. She definitely needs to be added to our OVAWeb!!!