I have one lease with 2 tenants. One wants to move out and 1 wants to stay. Does that terminate our lease? and can i ask the remaining tenant to leave
If the lease is still in force--i.e. the term of the lease has not ended (for example, it's a one year less that doesn't end until Feb.)--then even if a tenant wants to move out, the lease is still in effect and the tenants still owe rent. A tenant may not simply move out mid-term any more than you, as landlord, could evict tenant's mid-term unless they were not paying rent or otherwise violating the lease.
You may choose to allow the lease to be terminated if the other tenant moves out. Or you may choose to allow tenant 1 out of the lease if tenant 2 agrees to take over the whole amount. But that is your choice. Under the law, if the lease is still in effect, then a tenant may not simply decide to move out and the two tenants are together or jointly responsible for paying the full rent until the end of the lease.