I have noticed that Harry does this thing when he gets nervous and sexually aroused by Louis. These are a few examples, but he actually intertwines the fingers of his hands and grips as some sort of control or something. I love the last one too after Harry sees Louis riding in a chair he has to do the “hand grip” because I swear he wants to put his hands all over him.
Here is another one :) hmm you love bed huh Harold? with who I wonder?