His Hidden Purpose (1918)

The movie starts out with Marie as The Girl in the Case in love with Neal Burns, “Her Sweetheart.” But her dad wants her to marry someone else (Chester Conklin) and takes her away on vacation to get her away from Her Sweetheart. He follows them, disguised as a widow. There is a genuinely funny scene where Marie is disguised as a man to go meet her boyfriend disguised as a widow, and slapstick happens which results in Chester being found in his underpants with the widow in a barn.