We're looking at some really nice fares available from STL to TPA on Southwest ($44). We've never flown Southwest. DW and I are both Pooh-sized -- are they going to make us buy two seats each? We both can use standard airline seat belts (no extenders), and we'll have two little kids to sit next to.
We've never had a problem with Allegiant or United; just wondering how Southwest and/or their St Louis or Tampa people are about this.
Thanks in advance.

Thanks in advance.