1x31 - The New Adventures of Lucky Luke

Lucky is sent to check on Fort McCallister, which guards the Fake Tattoo Indians. He finds everything is peaceful. The commander's elderly but bossy mother, Julia, meets and falls in love with the chief's equal old and senile father Trilling Otter, which the brothers-in-law-to-be want to prevent at all cost. So the lovebirds elope.