[stunnel-users] client and server together?

I have a situation in which I have a client system, a middle-tier application server, and a backend database. The middle-tier takes info from the client and sends requests to the database, in other words the middle-tier has to act as both a client and a server in different parts of a transaction. Is it necessary that I run two instances of stunnel, one with an stunnel-client.conf wherein client=yes and another instance with stunnel-server.conf wherein client=no or is it possible to configure a single stunnel to do this? I would guess it would be kind of like having "client=yes|no" at the service level; this is not an option as far as I can see from the man page for 4.12 but I figured I could at least ask.