How do you know if someone has a crush on you?

I am trying to figure out if my friend (s) there is more than one obviously are alluding to liking me or if they are just making conversation. We are not super close but I feel like they are trying to leave the friendzone because we are always joking but they are always making jokes as if they have a crush on me. Exhibit A is one person. I am always joking with him and asking him to bring me food because that is our inside joke so every time that they see me they joke or tell me that they are going to bring me food but they never do. I obviously am serious and I know that they know I am. They are super sweet and always go out of their way to help me as much as they can and are always staring at me nonstop. We walked past each other and i accidentally brushed his hand and blurts out jokingly "Why are you trying to hold my hand" not only that one of our friends were jokingly blowing kisses to him while i was around and he comes up behind me whispering "Don't get jealous we are just friends". Now why would he go out of his way to do that? Exhibit B. We are always laughing and roasting each other and making each other laugh we are like bro and sister and always around each other. He loves seeing my goofy side and when he first met me he thought i was really quiet until i started feeling comfortable around him and he feels the same. I made a joke with him the other day and he whispers "How close are you trying to get to me cause i can roast you even more in a loving way". I am so confused like what does that mean? Advice? Me i'm always joking around with them but how do you know when they are actually serious? Like both of them are really good friends and we spend everyday with each other so i know the potential of developing feelings is a possibility for us, but I know what if feels like to fall in love with your friends only to make it awkward and I am not trying to have feelings and have it not work out

How do you know if someone has a crush on you?
Post Opinion