I know my friends username but don't know how to search him
Most Helpful Girl
You can either go to Google and type "GirlsAskGuys hi13hi" and your profile would come up in the search results.
You can go directly to their profile from here by using the URL www.girlsaskguys.com/user/
then their username.
For example, yours would be www.girlsaskguys.com/user/hi13hi
You must know the exact username in both cases, misspelling won't get you there.
Other than that, you'd just have to see them in a thread at some point.2