Sans is a MONSTER and not a HUMAN, so he doesn't follow HUMAN biology like a HUMAN skeleton. Same with Gaster and Papyrus. 

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That was the issue, with two people who had been best friends for the longest of time, because it was usually those types of people who were completely oblivious to the way they felt about each other. "They're just nice to me because they're my friend" or "we spend so much time together because we're best friends". It was the same usual excuses, and it was the same excuses that Chara wanted to use. And so did Asriel. Because of course Chara couldn't be the only one with a possible crush.

Matter of fact, the goat had already had a crush on the human girl for... A long time. Probably at least a couple of years, and he never really bothered to make them known. Not because he didn't want to. But because... Admittedly, he was afraid to. He knew how Chara looked at him. She saw him as her best friend, nothing more. That was how it seemed to him, with the way she talked about how she didn't feel like she was girlfriend material, or that she could see herself getting married. So, it made it  harder to gain the guts to confess. He almost had on a couple of occasions, but it became harder and harder to even do that. 

In the past, it had been pretty easy not to be that bothered about how he felt. He was only happy enough to be around Chara, and just being in her presence was enough to make him feel all fluffy inside. But lately, at least for the past year or so, it felt like it was making him more sad than happy to feel this way, only because he wasn't sure if Chara returned his feelings or not. He could take the risk, and ask her, but he had the fear of being shot down, of making things awkward, of ruining everything... He cared so much for her to the point he would rather hide away his feelings than lose her, even if it hurt to keep his love buried away deep inside of him. 

But he knew he couldn't keep dealing with it all alone. Which was why he wanted to talk to his dad. It was nice, because Asgore actually put more time aside to make time for him, or Chara, or Toriel, which made him smile because whenever he did end up going back to his old home where his mother still lived, and he saw Asgore there, the atmosphere between the two goat parents seemed much less tense, and like it was still steadily improving. He even saw Toriel smile towards his father on a couple of occasions, and it was things like that that made him hopeful.

So, here he was, finding himself sitting in his father's office, on the opposite side of his desk. It was anything but intimidating with the way the goat man smiled towards him, seeming happy to see him, while Asriel found it difficult not to smile in return. His dad had definitely seemed happier too, which he couldn't help but notice. "Hey, dad... Thanks for taking the time to talk to me today." The youngest goat said, really appreciating the fact that he'd take time out of his work schedule to do this. He didn't tell Asgore what he wanted to talk about, but he did let him know that it was a big deal to him, so he needed advice.

He wasn't yet sure if he would even mention it was Chara he was feeling this way towards, but he would just have to see how the conversation would go. "It is no problem, my son. After all, I have been wanting to make more time for you, and Chara, and my dear Toriel." Asgore spoke softly, causing Asriel to nod and widen his smile a little when his dad said that about his mom. He loved it when it was so clear his parents cared about each other; he hated when they fought and when they acted as if they didn't care about each other. "So, what is it that you wanted to talk about?" 

"Well... It's, um..." Asriel started, now all of a sudden feeling nervous, as he wasn't actually sure of how to start. Of where to start. It felt a tiny bit awkward to be talking to his parent about this, when he was an adult himself, he wasn't a child or a teenager anymore. However, he knew he couldn't just rely on his own thoughts, as they weren't getting him anywhere. "...What was it like when you fell for mom?" He decided to ask, which caused Asgore to let out a small chuckle at such a question.

"...I see." Asgore said, causing Asriel to raise a brow. "Well... That was quite a long time ago, but I do remember what it was like, clear as day. To be deadly honest, I was terrified." Asgore told his son truthfully. "I had no idea of how to tell her, or if she would return how I felt. She was this amazing, beautiful, young woman, and I was thinking... There was no way she would feel the same." Asgore explained, while the son carefully listened, beaming at the story his father was telling him. "But I knew that if I didn't tell her, I would have regretted it, horribly. Our parents hadn't liked us being together, but we did not care, because our love for each other only ended up being so strong." Asgore finished. "I already have a feeling you have a reason for asking this question." 

"Y-Yeah, well, I..." Asriel scratched behind one of his ears as he anxiously laughed. His parents hadn't been supportive of his and Toriel's relationship, huh? So, he knew what it was like when your mother and father didn't approve of the way you felt for another person. Surely, if he knew what it felt like, he wouldn't strongly disapprove if he just told him how it was. "I have feelings for Chara." Asriel bluntly admitted, but his eyes trailed towards the ground as he frowned. "...I have for years, dad. And I... Lately I've really been wanting to tell her, but I don't know how." 

For a moment, when he had said that, it remained silent, and he was sure that if he looked back at his father, he would be giving him a disapproving look. When he looked up, that didn't appear to be the case, as his dad was still beaming from ear to ear. "I've always known, Asriel. Your mother has always known." Asgore replied, seeing his son's eyes almost pop out of his head at such a comment. The father softly laughed. "We would see the way you would look at her, and we found it... Adorable. It somewhat reminded us of what it was like when we were growing up. We only didn't say anything, because we didn't want to embarrass you." 

"O-Oh..." Asriel stammered. 

"I know how it feels to be scared, son. But you shouldn't keep how you feel locked up forever." Asgore said. Doing that to yourself wasn't healthy, especially with such a strong emotion like love. It was funny, how love could make you feel so warm and fuzzy, but at the same time it had the capability to make you feel so painful and sad on the inside, if you kept it hidden away. "You need to find the perfect time to confess to her, but don't keep leaving it for too long. Because someday, she might end up with someone else, and you will only be angry at yourself for not saying anything because of that." 

"Yeah... I know. I've really been wanting to tell her lately but..." He shrugged. His fear of making things weird had been getting in the way of him trying to do that. There were many opportunities he could have had to tell her he loved her, and then he could only beat himself up afterwards for not saying anything. Such things made him wonder if this is how Sans had felt towards Frisk. Of course, his situation had been slightly different, as he had to suffer even more, seeing someone else with the girl he was in love with. It wasn't like Asriel had to see Chara with someone else, but it was still frustrating, knowing he could tell her but... He just wouldn't.

As he was talking to his father, Asriel heard the door open and he turned around in his seat, only to see his mom - Toriel - standing in the doorway. "Oh, hello my child!" Toriel smiled widely, coming over to Asriel to pull her into her arms, (as much as she could with him sitting in his chair), and she kissed him on top of his head. He let out a small yelp of surprise, but couldn't help but laugh a little, especially when his mother seemed in a good mood. "I wasn't expecting to see you here. Sorry, am I interrupting something?" 

"Oh, no, I was just about to leave." Asriel told her, going to stand up, before looking back at his father. "Thanks, for talking to me." He said, feeling like it might have helped a little bit, as he had a little more to think about on how he might be able to tell Chara the truth. Asgore of course said that it was no problem, and he went to leave both his parents, wondering what they were going to be talking about. But he allowed them to have their privacy as he left the room. Now he just really had to think...

How would he tell her?