Reality is not always a factor when it comes to TV relationships. Actually, it usually isn't. Often, two characters that would never come together in real life are forced into a relationship for any number of reasons. It's not really a problem for most TV viewers because they understand that entertainment value will always trump reality.

That being said, there are some on-screen relationships that make perfect sense. Then there are the head scratchers. Below is a sampling of the latter. Please note, just because these relationships are unrealistic doesn't necessarily mean they are bad, frustrating or boring. This is not a "worst TV couples" list, but rather a list of the most unrealistic.

That being said, a few of these are pretty downright awful.

Fred & Ethel ("I Love Lucy")

The original unrealistic couple, this pairing from back in TV's "golden age" works from a comedic standpoint, but that's about it. The contempt that William Frawley and Vivian Vance had for each other off screen is well known, but their fractured professional relationship had no bearing on the realism of their fictional television marriage.

What made their relationship so unrealistic was the extraordinary age difference (Frawley was 22 years older than Vance) and complete lack of chemistry. In fact, if an unenlightened viewer tuned in to "I Love Lucy" for the first time, they very well might get the impression that Fred is Ethel's cantankerous father whom is in her care. Now that would have made some sense.

Beecher & Keller ("Oz")

This bizarre coupling of a tortured soul and a sociopath could only have been born in the Oswald State Correctional Facility. The tumultuous relationship between Beecher (Lee Tergesen) and Keller (Christopher Meloni) was an important component of the critically acclaimed series, but it was also utterly unrealistic - even by prison standards.

The fact that Beecher could love Keller after being mentally and physically tortured and abused by the man is hard enough to accept. The fact that Keller could care about any person, in the slightest capacity, is even more preposterous.

Peter & Lois ("Family Guy")

The inexplicable pairing of an overweight man and a slim, pretty woman has become an especially popular convention in the last 10 years or so. Some of those couplings are more realistic than others, but none is less feasible than the "Family Guy" union between Peter and Lois. Not only is Peter morbidly obese, but he is a selfish and uncaring individual who has never demonstrated the least bit of love for his wife. He makes Homer Simpson look like a model husband by comparison.

So why did Lois, a sweet girl from an extremely well-to-do family, fall in love with the classless behemoth Peter? Who knows? It sure doesn't make sense, but then again good comedy doesn't always need to.

Worf & Troi ("Star Trek: The Next Generation")

The love affair between Worf (Michael Dorn) and Troi (Marina Sirtis) that blossomed during the show's final season felt forced and unnatural. Thankfully, it was short lived. It did provide the audience with some excellent "Awkward Worf Moments" (a staple throughout the series' run), but that's about it. A Klingon and a Betazoid? Come on!


Cordelia & Xander ("Buffy the Vampire Slayer")

Cordelia (Charisma Carpenter) circa season three of "Angel," maybe. Cordelia circa season two of "Buffy," no way! It was a great pairing and all but completely unrealistic. At that point in the series Cordelia, despite a few brushes with the supernatural, was still the popular and shallow rich girl who would have never allowed herself to date the awkward social outcast that was Xander Harris (Nicholas Brendon).

The character of Cordelia would go on to grow tremendously. Arguably, she has one of the most dynamic character arcs in the Buffyverse. Still, at that point in her life she would not have been caught dead with Xander. Not to mention alive.