I have to agree with everyone else...It will cause them way too much stress...and a 5 gallon doesn't have enough space for them to hide from eachother! It's really a bad idea to house a female and male betta together..Because it will just stress them both and could cause many problems and death. They won't live nearly as long as they would seperated. They will end up killing eachother like everyone else has said.
R.I.P I will never forget you Alexander. You brightened my life
♥Alexander ♥- Maroon VT 11/14/10
I miss you every single day. You were more than just a pet to me. I love you forever and always. I hope you always know that I would have done anything to save you.