The elderly lagomorph was green with jealousy.
(Not in a literal sense, though. He would've bitten Discord if the draconequus did that to him. It wouldn't have been the first time the rabbit did that to the draconequus either. He still remembered the time when he bit Discord's snout when Fluttershy and Discord were cuddling. The lagomorph was put in the corner by Fluttershy for that little action.)
Angel was not the most pleased that Discord moved in after their marriage, let alone them even getting together. While he was happy that Fluttershy found someone special and was happy, her choice in a mate was...questionable at best in his opinion. He disliked Discord rather strongly, and he recalled all the times the two of them fought for her attention. Eventually, the two sort of settled their differences once they realized they both cared for Fluttershy and they started to try and tolerate each other for her sake.
That didn't mean he suddenly liked Flutter's mismatched lover, though. Quite the contrary, in fact.
He was no happier when he heard that Fluttershy was pregnant. To Angel, this news meant that all the attention would be diverted to her new kit. Or foal, as Angel remembered ponies called their infants. When the little filly, who Angel learned was named Wildflower, was born, Fluttershy still made sure to make time for her beloved rabbit, but he still wasn't pleased by the situation.
He thought all this as he stared up at his owner feeding the little filly with a bottle. The foal was a pegasus like Fluttershy, but inherited some of Discord's colors. She didn't seem to have the magic of her father, much to the buck's relief.
Fluttershy took the bottle from Wildflower once the foal was finished eating and carefully patted her back. The little filly burped shortly afterwards, causing Fluttershy to smile happily. Angel grew more bitter. He wanted to jump up and take the attention Wildflower was getting and transfer it towards him. But not only is he getting older and he couldn't move quite as well as before, but he might hurt the filly if he misstepped and, as much as he wasn't fond of the filly, he didn't have the heart to actually hurt her.
So he just sat there, silently let his jealousy fume higher and higher. Fluttershy looked over his way and seemed to notice that something was up as her expression changed to a sympathetic frown. Not wanting her pity, Angel looked away, trying to act apathetic. Fluttershy saw right through his act, though.
"Angel..." She called out to him in a motherly tone. He continued to ignore her, now crossing his paws over his chest and pouting.
Fluttershy put Wildflower in the nearby bouncer before walking over to the lagomorph and kneeled down to his level. He knew she was there, but just continued to keep his gaze away from her, pinning his ears against his head.
"Angel, I know something's bothering you. Do you talk about it?" She said gently with a caring smile.
Angel didn't budge, but like the other times Angel was being stubborn, she pressed forward. "I want to help. What's the problem?"
Angel sighed, knowing she wouldn't let up if he didn't tell her, so he decided to tell her. He told her how he had been feeling, all without turning around. The old buck wouldn't let her know how much he had been bothered by this and he didn't trust his facial expression to betray what he was feeling, but she still saw how upset he was, and it broke her heart to see her precious Angel in pain.
"Angel," she started after he stopped talking, "you know just because me and Discord have a new filly doesn't mean I don't love you any less, right?" Angel reluctantly nodded once. "I know you still don't like Discord and...well...he doesn't really like you all that much either, but you're a part of this family too, Angel."
Angel still didn't look towards her. Fluttershy sighed. He could be so stubborn sometimes. Suddenly, she had an idea. She walked over to the bouncer and picked up Wildflower before putting her down next to the grizzled lagomorph, her standing nearby to make sure nothing went wrong.
Noticing that somepony else was now present, Angel finally turned around, seeing the little filly looking right at him. Her teal-and-red eyes looked at him in intrigue. The foal walked over to him and made some weird gurgling noise the buck couldn't decipher. He raised an eyebrow towards Fluttershy, wondering what her plan is. The filly's light gray muzzle nudged his scruffy fur in curiosity.
He felt so awkward right now. This was the closest he has ever been to the filly, having intentionally keeping his distance before. As Wildflower nudged further into his fur, Angel sighed and lightly patted the top of the filly's head.
Fluttershy smiled at the sight. She laid down as she saw her daughter enjoy her time with Angel, every now and then making sure she doesn't act too rough around the bunny (and also to make sure Angel doesn't hurt Wildflower). Even if he doesn't open up much towards Wildflower or even outright despised her like him with Discord, she still hoped more interactions like this with her supervision will make it clear to Angel that she still loves him and that he's still a part of the family.
Angel woke up from his nap as he heard the door latch close. He looked up from his bed and saw his caretaker and her annoying husband, along with the now two year old filly known as Wildflower and a new little bundle in Fluttershy's hooves as she hovered. He knew that it was their second little foal. When he learned Fluttershy was pregnant again, his reaction wasn't as bad as before. Sure, he still wasn't happy about the situation, but Fluttershy's plan with Wildflower made his envy mostly go away. There were still moments his jealousy would pop up again, but the feelings would usually go away fairly quickly.
He decided to check out the new baby. He stood up and stretched before hopping over. When Wildflower looked over, she exclaimed "Angel!" He rolled his beady eyes at the toddler. He still wasn't really fond of her, but rather than getting huffy, he just let the energetic toddler be.
Discord bent over and roughly patted Angel's head. "Good evening to you, little Demon." Discord said with a smirk.
Right back at you, wormhorse. He snarked in reply. He heard flapping wings behind him and he looked up, seeing his owner smiling caringly at him. She seemed to know what he wanted and held out the bundle for him to see.
"Angel, meet our daughter, Raven." The grizzled buck looked at the tiny filly wrapped in a white baby blanket. Her mane was black like Discord and her head was gray like him, but her open eyes were identical to Fluttershy, minus the pink color of the irises. His own ears flicked as he looked at the filly's droopy bunny ears. Raven stared at the elderly rabbit with interest, strangely perceptive of her environment for a baby who was only a few days old.
The baby smiled towards him and laughed happily. Angel allowed a little smile to appear on his face as Raven babbled. This, in turn, made Fluttershy smile widely with tears in her eyes.
Angel seemed to accept Raven into their family, as she has accepted him into her family when she found him so many years ago as a filly.