-- coming home -- holding hands, literally reaching out to you -- apologizing -- acknowleging his selfishness -- taking the emotional risk of sharing with you that he ALSO wants the R to work
Regarding trying to force counseling, I'd strongly suggest you put that idea on hold for a few months and revisit it after that. Too many people here decide that will be their very artificial line in the sand.
Instead, focus on YOUR boundaries. It is up to Gabe to learn how to live with those. If he struggles, it is up to him to figure out how to cope. IC might or might not be helpful to him. HIS choice.
But, one of YOUR OWN boundaries should be that you don't try to run other people's internal lives or make their choices for them to control the world.
Boundary: I require a stable productive partner.
Sharing: I found that my IC has really helped me become more stable and productive.
Controlling: You can't hold down a job, you can't see me until you have 6 months of career counseling.
Boundary: I require respect.
Sharing: Sometimes when I feel bad about myself, I twist it into something bad about you.
Controlling: There's no way you can learn to treat me decently unless you go into intensive psychoanalysis, so you have to go.
IC is really something that has to be totally freely chosen to be useful, and just because you find it important to your growth does not mean that Gabe either requires it or would find it useful. People can certainly grow plenty without it.
That being said, I think it is FINE to express that you'd really like to have Gabe join you in a session or two with your IC to work on something specific -- like, building trust, devising a plan to avoid another cheating scenario, etc... And, when things settle down a bit, asking him to join you in MC to help build a great R that works for both of you sounds fine. "I'd like to see blah blah happen with us... MC could be a useful tool, I'd like to try it with you..." I'd just avoid making it a requirement or test of sorts. Don't dictate, don't control, don't punish, don't assume you "know" what Gabe "needs" to fix himself. That's his job, and you really don't know what resources he needs to make that happen.
Rs can heal, Rs can grow, Rs can become what you want all without therapy.
The requirement or test is whether things are moving in a positive direction that works for you, NOT the particular means for such progress.
