I'll not question the authoritative voice of Stan Laurel who says he considers this the first official Laurel and Hardy film. They were both separate players signed to Hal Roach contracts when Roach decided to team them. The idea was genius, but the separate contracts would cause some problems for the team and for Roach about a dozen years later.
But for now Putting The Pants On Philip has a bit of an unusual situation for the guys. Hardy is an older middle aged man and Laurel his nephew come over from Scotland. Being a true Scot Stan wears proudly the tartan kilts of his clan and he has a libido in this that Harpo Marx would envy. Keep him away chasing girls says his mother to her brother Ollie.
But a Scot in kilts is catnip to those flapper girls of the 20s and Ollie sees his duty, he has to get the nephew into pants so he won't be so conspicuous.
Most of the humor revolves around the mystery of whether the Scot wears undergarments with his kilt. In Laurel's case he does and he doesn't.
The last bit was something I think Stan might have heard about involving that famous story of Sir Walter Raleigh and his cape. Ollie climaxes the film with an unexpected surprise there. One of the great sight gags that so typified Stan and Ollie's work.