Hi, and welcome.
You might want to do some reading around here on mono/poly. There's tons of threads about it.
I'm a little confused as to why you would want him to have a new relationship if he's mono. If he really is mono, would you not worry about him switching his affections from you to a new person? I would.
There are threads of folks discussing feeling guilty about wanting other relationships, so they try to get their partners to have others. If he's okay with you seeking others, believe him. Not good to change his behaviour to assuage your guilt (if that's what it is).
Just some thoughts; and suggestion that you read around here, you will find similarities.
Love is that condition in which the happiness of another person is essential to your own...
Robert A. Heinlein
Me: female, bi, (formerly hinge of a vee)
with FirstBoyFriend (FBF)(moderately long-distance)
and no longer with CurrentBoyFriend (CBF)(who lives in the apartment building next door)