Is it normal to want to finger another girl

Ever since I was at the park with two of my friends,we were in the play area,and one of my friends was sliding down the slippery slide,she had a short dress on which had gone right up her legs passed her knickers,my friend laughed and said to her that we could see up passed her knickers,she just laughed,we then went around to go up the ladder to the top of the slippery slide, but our other friend ran passed us to go up the ladder first,she was laughing,when she started climbing up the ladder my friend moved her hand up under her dress,we both laughed,I then saw her hand go right up her leg,she stopped climbing up the ladder and said to my other friend to stop that,and she was laughing,I laughed and said to her to finger our other friend,she then came down the ladder and as she turned around I saw my friend move her fingers up under the leg of her knickers,her dress was right up her legs,and I saw her hand go right up under her knickers and she stopped laughing,after a little while she moved her leg and my friend looked at me and said that she was all the way up inside her,I could see her hand moving under my friends knickers,she smiled and looked up at our friend and said that she had her finger all the way up inside her,and that it felt nice,she then took her hand away.
Since then I've had the urge to finger her to see what it feels like to touch another girls pussy,and what it feels like to finger another girl,is that normal to want to do that to another girl?