It's no secret that Saved by the Bell's Zack Morris was a little selfish. His plans in the series were often about boosting his own grades, his own wallet, or his own social life — sometimes at the expense of his friends. The schemes he came up with also played a role in his dating world, making it clear that he wasn't the best of boyfriends.

RELATED: 8 People Zack Should Have Ended Up With In Saved By The Bell Other Than Kelly

To be completely fair to Zack, his bad decisions and his selfish actions were often accompanied by a learned lesson. He still had a lot of growing up to do during the years Saved by the Bell aired, but he sure taught the audience a lot about what not to do in relationships.

Zack Lied About His Age

Zack, Slater, and Screech are surprised in a club in Saved By The Bell

Zack Morris was the kind of teenager who worried more about getting the attention of a girl than he did about what would happen once they were actually in a relationship. He lied about his age multiple times to girls was interested in, which didn't go well for him.

The first time was in the series that came before Saved by the Bell, Good Morning, Miss Bliss. As an eighth-grader, Zack met an older girl over the summer and lied, telling her he was in the same grade as her. It came back to bite him when he ran into her at school and couldn't keep up the lie. Likewise, he met a college student while he was in high school, and pulled the same scheme, trying to get a date but getting found out in the end.

Zack Used Subliminal Messaging

Screech and Zack high five while standing with Lisa and Kelly in Saved By The Bell

Zack wasn't actually in a relationship when he and his classmates learned about subliminal messaging in school. He wanted to be, though, which is why he decided to use his friends' interest in a new music tape to leave messages in the album that encouraged Kelly to find him perfect. This is easily one of the worst things Zack has ever done.

It didn't take long for Kelly, Jessie, and Lisa to figure out just what was going on and go to a teacher for help. While everyone treated it as Zack being a silly schemer, psychologically manipulating some of his closest friends to get a date is definitely a red flag.

Zack Tried To Trick Kelly Into Giving Up Paris

Kelly And Zack side by side in a promotional image for Saved By The Bell

When Zack made the questionable decision to take photos of the girls' swim team (without their consent) and sell calendars of them, he ended up getting Jessie, Lisa, and Kelly noticed by a magazine. Kelly was offered a chance to model in Paris for the magazine.

Rather than encourage Kelly to take a great opportunity, which would only have lasted for a few weeks, Zack decided to trick her into thinking her friends were mad that she was leaving, isolating her, and making her doubt her choice. He did eventually own up to the fact that he was afraid she would forget about him, but it was still a horrible thing to do to her.

Zack Ditched Almost Every Girl After One Date

Kristy embraces Zack in the gym in Saved By The Bell

There's nothing wrong with having a social life or a dating history. Zack, however, didn't even take the time to get to know the girls he was interested in. For him, it appeared to mostly be about the chase.

RELATED: 9 Times Zack Was Actually A Great Friend In Saved By The Bell

Zack would spend a large chunk of his time pursuing a girl. When she finally agreed to a date, often because he used a scheme to get his way, he would act like they were suddenly the new "it couple" in school but would never see her or talk about her again. Most of the time, the girl on the date didn't end the night happy with him, but there were times, such as with wrestler Kristy, that it appeared the two hit it off. Kristy, however, never got another date.

Zack Didn't Tell Kelly About Nicki

Nicki and Zack talk by his locker in Saved By The Bell

When Kelly and Zack did start dating, he still had trouble with the idea of being completely open and honest. No matter how much he cared about Kelly, he always made things more complicated by hiding things from her, like her little sister having a crush on him.

Zack mistakenly gave both sisters the wrong advice when they called his Teen Line, leading Kelly to think they should break up and Nicki (who was only 13) to think they were dating. All he had to do was talk to Kelly about what happened, especially since Kelly already could tell Nicki had a crush on him. Instead, he ended up with Nicki hurt and Kelly confused.

Zack Hit On The School Nurse

Zack meets the new nurse in Saved By The Bell

Zack and his friends attended high school during a time when the school gave comprehensive physicals and flu shots to their students. The exam happened to coincide with Zack having just asked Kelly to "go steady" with him.

Kelly asked for a night to think about it, which made Zack incredibly nervous, but as soon as she was ready to say yes, he was busy obsessing about the new school nurse. He completely ignored Kelly for the entire day once he met the new addition to the faculty. Even when Kelly gave him her answer, he didn't remember the question. Not a great way to treat someone he wanted to have a relationship with, and considering he spent most of Saved by the Bell wanting to be with Kelly, it made no sense.

Zack Handed A Date Over To His Friend

Lisa, Nikki, Screech, Miss Bliss, Mikey, and Zack in Good Morning, Miss Bliss

When Saved by the Bell was still Good Morning, Miss Bliss, Zack accepted a date to a school dance not knowing that his friend Mikey had a crush on the same girl. While Mikey and Zack spent a good chunk of the episode upset with one another, Zack decided to make it up to Mikey by just giving him his date. As he explained it to Mikey, his curfew was earlier than Mikey's, so it would work out.

RELATED: 8 People Kelly Should Have Ended Up With In Saved By The Bell Other Than Zack

Luckily for both Zack and Mikey, the girl in question didn't mind hanging out with Mikey for the rest of the night. The trouble is Zack didn't even take her feelings into account, just Mikey's, showing how little thought he put into his relationships outside of how they affected him.

Zack Objectified Kelly

Lisa, Kelly, and Jessie stand by card board cut outs of themselves in Saved By The Bell

Long before Zack actually dated Kelly, it was clear that he wanted to be with her. This wasn't just demonstrated for the audience by Jessie calling out his crush in class — Zack also had a life-size cardboard cut out of her in her volleyball uniform in his room and a poster of her he could access with a remote control.

While the audience might have found that funny at the time, it's a little creepy by today's standard, especially since he managed to win Kelly over and still did things like take photos of her without her permission. It's definitely one of Zack's worse traits in Saved by the Bell.

Zack Proposed To Kelly To Get His Way

Zack and Kelly stand together on their wedding day in Saved By The Bell

Zack often found his relationship with Kelly "threatened" by outside forces when new opportunities presented themselves. In high school, it was modeling. In college, it was three months away for an academic program.

Again, instead of understanding what a great opportunity it was for Kelly, Zack focused on his own fears about losing her. He also, again, didn't talk to her honestly about it. Instead, to show he was serious about their relationship, he proposed. On the one hand, it was a sweet gesture. On the other, Zack wanted to manipulate Kelly with the big question so that she either wouldn't leave for the trip or become interested in someone else while she was gone.

Zack Let Kelly Come Between His Relationships

Zack and Kelly sit together in a booth in Saved By The Bell

It was evident to anyone watching Saved by the Bell that Kelly was Zack's ultimate dream girl, and she was more than just a crush. While he did scheme a lot and make bad decisions in their relationship, he also tried hard to make her happy. He tried so hard in fact, that she got in the way of the other relationships in his life.

Not only would he drop any girl if Kelly showed an interest in him, but when they broke up, he also intentionally brought dates to her workplace so he could see her reaction. In college, Zack ended his pursuit of his suitemate Leslie almost as soon as Kelly reentered his life. Despite starting relationships with other girls, Zack only ever wanted to be with Kelly.

NEXT: 8 Times Zack & Kelly Were Couple Goals In Saved By The Bell