my tenant is asking a combined lease possibility with her fiancé

[Yashar Fred]

a potential tenant is asking to be able to sign a lease WITH her fiance so that they meet the income requirement criteria (x3 the rent), 

What is a good way to do this?  She does not want to do a co-signer and is suggesting her fiance wants to be on the lease.

How else can it happen if not co-signing?

[Forrest Williams]

Have her sign the lease with her fiance. She may think co-signing means someone is signing with no intention of living there (like co-signing a loan for your child). They both want to live there together it sounds like. So let them both sign and you're good.