Three's Company S02 E04 Strange Bedfellows

"Come and knock on our door"

Chrissy and Janet go away on a trip, and Jack promises he won't throw a party. As soon as they're gone he goes back on his word. When Mr. Roper comes up to put an end to the party, he ends up joining in, but wakes up the next day in Jack's bed...WITH Jack, and he thinks he's gay.