In the episode "Jack's Tattoo" (8.16), Jack borrows Janet's suitcase. When Jack drops it, it appears to be filled with nothing but lingerie?! Might this be the only clear indication that one of the girls was sexually active? In various episodes it was made clear that Jack and Larry were, but because of the double standards of that time period, the topic seemed to be more or less off limits for the female roommates. No direct reference was ever made to Terri's sex life. Everyone seemed to be convinced that Cindy was a virgin, but she never confirmed or denied it. Any apparent reference that Chrissy made turned out to be a misunderstanding.

(Side note: one of the items is a see-through pale blue baby-doll nighty, not at all Janet's color. I'm shaking my head at her poor taste.)

I think you're overthinking it....the lingerie in the suitcase was the punchline for a joke. Seconds before we see it, Furley was ribbing Jack about being gay and Jack was being defensive. Then the suitcase opened, the lingerie popped out, big laugh.

Fun fact: in "Extra, Extra" in Season 7, we see Terri's mother give Terri that same blue see-through nighty as a gift. So there you go. It's not even Janet's! lol

Also, and I hope this doesn't break anyone's brain, but a woman can own and wear lingerie for one's own enjoyment of it. It doesn't automatically mean she's wearing it for someone else.

Even if we go along with your theory, the fact remains that the suitcase with the lingerie was buried in the bottom of Janet's closet. So I guess, whatever its use, it hadn't seen the light of day in a while.

I find the observations of both of the posters on this thread to be quite interesting. I am very impressed.