Help please!!!! I am really confused?

So I really like my friend. I'm 90% sure he likes me as well but he's making me feel really confused. I feel like he likes me but I also feel like he likes our mutual friend too. Anyways here's the reasons I think he could possibly like me:

-He sometimes will pay for my dinner

-He likes talking to me

-He has a nickname for me

-He touches me sometimes (i.e. he's squeezed my arm and played with my fingers before)

-He teases me for being short

-He's told me I looked nice a couple of times

-He invited me to this business meeting thing for his work, to the movies, and to a water park

-He asked for my number and he's randomly texted me a few times for no reason

-He asked me if I had a boyfriend and if I've been on a lot of dates

But these are the reasons I think he might like our friend:

-He teases her for being lactose intolerant

-He likes talking to her as well

-He also invited her to his meeting thing for work and to the movies

-He has her number

-last week we were all hanging out and she was kinda sick and almost threw up so he was comforting her and asking if she was alright and he put his arm around her

I asked his sister-in-law if she knew if he liked me and she said she didn't but that she can tell that he clicks with me and she said he doesn't click with just anyone. But it's confusing because I don't understand why he acts like that with our friend if does like me. Help me please!!!! What do I do? P.S. sorry for the long question!!!