I know I'm a hard doncil shipper but I'm secretly also a multishipper so...
Basically Cecil has the hots big time for both Omniman and Debbie for decades and this is a quick exploration of how that would affect him emotionally during canon events
Cecil has kind of a thing for Nolan and is in denial about it. Like yeah I'm just keeping tabs on the alien guy for uhhh research purposes. And when he eventually gets over the shame and comes to terms with how he actually feels about Nolan he knows it's a serious conflict of interest and his judgement is compromised. He's supposed to be monitoring and investigating a man he can't help but be attracted to? Can he afford to stay on this case? Can he afford to leave it? Can he even come up with a good enough excuse for leaving and just letting the grunts handle it?
And then Nolan introduces his new girlfriend Debbie and shit gets ten times more confusing for Cecil. Cause now not only is he crushing hard on two people at the same time, those two people are together. He's happy that they're happy but he gets a bitter taste in his mouth every time they kiss. He has no idea who he's jealous of. He puts a lid on that pot and lets those feelings simmer for twenty years, but they never go cold. He thought he had moved on, really he did.
And then Nolan stabs them both in the back.
"You hurt her, not me. She and I have that in common now." He meant that.
He wouldn't tell Debbie this but he feels like he understands her more because of how he felt about Nolan. To have so much love for someone and they turn out to be a monster. And if only Cecil didn't feel the way he felt maybe the betrayal wouldn't have been such a knife to the heart. And goddammit he wants to tell her so bad. He would never try to imply that their situations are comparable, I mean Debbie was the one actually married to him for Christ's sake. But he wishes she knew, that he understands even more deeply than she knows.
But he can't tell her, so instead he pulls strings to make Nolans old sci fi books profitable, to make sure the remaining Graysons will never want for anything. Debbie pushes him away anyways. That's ok. He's not mad. He understands why she think's it's a ploy for control, even though it isn't. He's actually kind of thrilled she turned down his offer, he always loved her fierce independence. He's glad Nolan didn't break that part of her.
He cradles her when she wails over the broken body of her teenage son, the son that could've been his. That should've been his. Cecil is a piece of shit, sure, but he'd never beat Mark to a bloody pulp for disobeying him (so he thinks). Nolan doesn't fucking deserve her. Maybe he never did.
I might be forgetting something mean he did but Cecil is always so tender with Debbie. Like she literally slaps him for fucks sake and he barely even flinches. Just gives her this apologetic look and basically tells her he deserved that (he did). He's such a jackass to everyone else but her, I don't think anybody else could've slapped him like that and either lived or stayed out of prison. And you might say he's just being kind to a grieving woman whose basically widowed. I'm sure he uses that excuse too.