It would be impossible for that scenario to happen because the SEC champion would get an automatic bid, and there can't be three teams from the same conference in the BCS bowls.
edit - trying to verify that rule, just to make sure.
Welp, i stand corrected.
No more than two teams from a conference may be selected, regardless of whether they are automatic qualifiers or at-large selections, unless two non-champions from the same conference are ranked No. 1 and No. 2 in the final BCS Standings.