I heard a rumour that hot women like chubby guys so i guess that could explain it.

But if you really think about it thereīs a very simple reason why Edea is with Cid think about it:

Cid ownes the Garden he is probably a rich man and Edea is simply trying to get all the money to herself after that fat loser dies.

You know what i bet thatīs why she became a sorceress too...Ultimecia didnīt really control her ohhhhhh no she just used her as an excuse to try and kill Cid and get his money that big ****.