First, Harry is often seen as the more aggressive and dominant one in the relationship. He is often seen making physical contact with Louis, such as putting his arm around him or kissing him on the cheek. Louis, on the other hand, is often seen as the more submissive and passive one. He is often seen looking up at Harry and smiling, and he seems to enjoy Harry's attention.
Second, Harry is often seen as the more sexually confident one in the relationship. He is often seen making sexual jokes and references, and he seems to be more comfortable with his own sexuality. Louis, on the other hand, is often seen as the more shy and reserved one. He rarely makes sexual jokes or references, and he seems to be less comfortable with his own sexuality.
Finally, Harry is often seen as the more experienced one in the relationship. He has been in a number of relationships before, while Louis has only been in a few. This suggests that Harry may have more experience with sex and may be more comfortable with being dominant in a relationship.
Of course, these are just clues and there is no way to know for sure who tops in Larry Stylinson. However, these clues may suggest that Harry is the dominant partner in the relationship.