Tenant pregnant and wants baby daddy roommate.

[Account Closed]

I owner occupy a one-bedroom duplex. I have a nice tenant that just renewed a 1 year lease. What I just found out after her renewing is that she is a couple months pregnant and wants her boyfriend (babys dad) to move in with her. Her boyfriend has a police record a page long and it's not pretty. Literally it's a page long and some of it is current. Normally I would not allow him to live there, but she is due in 7 months and her 1 year renewal starts next month. What's the best way to allow him to live there? I'd rather just her be on the lease so I don't have to deal with both of them. But I want him to sign something to obey the rules and regulations, without being on the lease. Is this possible? Are there better options? Thank you.