Three's Company S04 E11 The Love Barge

"Come and knock on our door"

Jack gets a job on a cruise ship and is invited to take only one guest. He has a choice between Janet and Chrissy and he sure doesn't want to take Lana of all people. So he makes it so Mr. Furley can go on the trip with Lana, who thinks that jack will be on the ship waiting for her.