But despite plenty of opportunities to explore Karen's bisexuality as more than just a running gag, the writers have so far insisted on keeping it to one-liners and innuendo. This may be in part because her comments about dating and relationships, like this one in Episode 19 of Season 5, also betray a decidedly heterosexual world-view:

KAREN: Well, deal me in. I've got a lifetime membership to the losers club. I've been dumped by one-ton billionaires, heads of state, and every member of Crosby, Stills, Nash, and Young, but I'm not naming names. What's so great about another person, huh? All they do is manhandle your boobs and eat all the ham.

Although she avoids gender-specific pronouns in this statement, the "person" she is referring to in the question "What's so great about another person?" is clearly male, as indicated by the qualifier "all they do is manhandle your boobs and eat all the hams" (which would never be generally understood to be describing a woman).

Karen's heterosexual identification is also apparent in explicit discussions about lesbianism or bisexuality, such as this one in Season 3 (Episode 3), when Karen is jealous of Grace's new boyfriend and Grace tries to cheer her up:

GRACE: Listen, I was sitting across the room, and I saw you, and you took my breath away.
KAREN: What?
GRACE: Yeah. I mean, you are such a sexy, beautiful, vibrant woman. Anyone would be so lucky to have you.
KAREN: [GASPS] Are you hitting on me?
GRACE: Wh-- What? No! Where do you g--
KAREN: You are! Oh, my god. You're a big lez.
GRACE: Karen--
KAREN: You know, people have always said you were, but I said, "No. That's just the way she walks."
GRACE: [DEFENSIVE] I have a sturdy gait.
KAREN: Honey, come on. Finally, an explanation for the chunky shoes and all the keys.
GRACE: No. No, no, no, no, no. See--
[GRACE TOUCHES KAREN'S SHOULDER. KAREN SHOOTS HER A LOOK AND PULLS AWAY SLIGHTLY]
GRACE: Look. Look. Um, Karen... I just sensed that you were feeling a little down, and I just wanted to make sure that you know how attractive you are.
KAREN: Hey, back off, Lezzy Borden. No means no.

Karen automatically concludes that Grace is a lesbian, rather than bisexual (probably because the writers couldn't come up with any funny stereotypes of bisexuals to play on), despite the fact that Karen is supposedly bisexual and the fact that Grace is clearly attracted to men. This is not a conclusion to which a bisexual woman would automatically jump.

Karen also clearly rejects Grace's advances here, contradicting Karen's frequent comments in other episodes indicating she would be interested in such a development, like this exchange with Grace in Season 5 (Episode 3):

GRACE: But it didn't feel right. I've got tell Will the truth--the whole truth.
KAREN: [SIGHS] Well, maybe it's for the best. Then you and I can move on with our lives. Out in the open to love freely.
GRACE: Karen, we're not a couple.
KAREN: Aren't we?
GRACE: No.
KAREN: Well, all I know is when I woke up this morning, there was red hair on my pillow and lesbian porn in the VCR.
[KAREN RUNS HER HAND THROUGH GRACE'S HAIR, AND SMACKS HER OWN BOTTOM. GRACE TAKES A STEP BACK.]

This kind of schizophrenic, contradictory behavior is characteristic of Karen's sexuality (and her personality overall): Karen might joke with her friends about hooking up with Grace or another woman, but when it comes to actually following through with it--especially if it's more than a one-night stand--she pulls back.

KAREN: Oh, Martina.

MARTINA: Karen, where have you been? I've missed you.

KAREN: Oh, honey, listen. I've got some bad news. I can't marry you. I'm in love with someone else.

MARTINA: But, Karen, I was straight before I met you.

KAREN: Well, that's the way the cookie crumbles, Marti.

MARTINA: Well, then who? And can she give you what I give you?

KAREN: You mean companionship, vitality, a sneaky drop shot? No, no. No, he's a doughy thing with squat little legs and a bad case of recurring psoriasis, but... I love him, and with my help... Oh! Who am I kidding? I just love him. Who knows why? I love Stanley Walker!