Cheating is one of those relationship topics. Eventually, someone is going to say something and something is going to happen and be said and everyone who knows knows how this goes down. Good summary?

There are aspects I can post about this, but, I have never cheated and (to my knowledge) I have not been cheated on. This is mostly because I normally launch into this monologue:

Manda: Look, I like you. If you ever want to do someone else or be with someone else, just tell me first and it will be fine. You won't get to come back to me but I won't stop you. If I ever want to do or be with someone else, I will do the same. Just don't lie to me.

Couple that with my "pancake" monologue (located at the bottom of that post) and I think I make my point.

Exclusive and Non-Exclusive
If you are actively dating, putting some effort into it, you'll probably be seeing more than one potential mate at a time. This is called being "non-exclusive." You assume at one point in the dating situation, you will find one person you want to focus on and then you'd be "exclusive" and not dating others.

For your own benefit, make this a clear line. At least in your own head. When you are in a relationship that you believe in exclusive, just throw your feelings out there. I know there is always that fear of rejection, but, rejection is probably the better of the two evils: rejection vs. thinking-you-were-in-an-exclusive-relationship-and-not-saying-that-you-thought-you-were-and-then-finding-out-your-mate-is-seeing-someone-else-and-feeling-rejected-and-humiliated-and-wishing-you-had-said-something-earlier.

Remember, you cannot require of others what you do not require of yourself.

I try to be upfront with the "exclusive" and "non-exclusive" stuff. In my mind, the conversation goes something like this:

Manda: Are you seeing anyone else?
Boy: No.
Manda: Me either. I suppose we are exclusively dating, then, correct?
Boy: This is exactly how I feel. I am happy that you brought this up. You are pretty. Let me buy you expensive things.
Manda: Excellent. 

Of course, it normally goes like this.

Manda: I don't know what other hussies you are smooshing.
Boy: Smooshing is a funny word. Haha.
Manda: I'm funny and attractive.
Boy: Haha. Did you want to do something? Maybe grab some food?
Manda: Is there bacon? Bacon is good.
Boy: Is something bothering you?
Manda: Did you want pancakes?

Cheating And Not Being A Jerk
There is always some argument about "what is cheating?" whenever I find myself involved in a discussion about it.

Cheating is simple. When you are involved with one person and then get involved, however temporary, with another person you are cheating. The key is this is all done by either by withholding information or lying. If you cannot openly talk about being involved romantically with another person, you are cheating.

Cheating is a breach of trust and in that regard, it really comes down to the hurt party. If you don't think playing tongue hockey with a forgot-your-name at a bar is cheating, but your mate is hurt by this, it's cheating.

Jealously
I try to be as open and honest about things as possible when in a relationship. I hope this builds up a good level of trust between me and my current mate and reduces jealousy. And I would never cheat. Period.

I have only seen jealously spike in two of my boyfriends.

• One was upset over the connection between me and my guy-friend in college. I had been dating my boyfriend at the time for about two months, I had known my guy-friend for about a year. It was actually a more manipulative move on my then-boyfriend's part. He didn't care so much I had this friend who was male, he was looking for ways to get attention, and accusing me of cheating (however superficial) was one of them.
• The other was when I visited a guy-friend in New York City where he was my tour guide, my then-boyfriend told me he was a little unsure about the situation. I assured him I was not boinking my NYC friend. I also explained I had set up the trip months before we started going out.

The best I can do is explain my relationships with my guy-friends. I mean, they are going to be around as much as my group of girl friends.

Snooping
I know a lot of girlfriends who take any chance they get to go through their boyfriend's phones, emails and papers. I find this not the best way to go about doing anything. Again, always a breach of trust. Plus, I wouldn't want someone going through my stuff without my permission. I would prefer to be asked about things.

The defense to this is sometimes more preventative. The reason, a friend pointed out, is it is better to figure out s/he is cheating on you on your own as as soon as possible. It feels defeatist to me. I prefer to honor someone's privacy and act honorably on my own and risk getting humiliated and hurt rather than cater to insecurities and fail to address them head on.

Of course, I am equip with a gypsy instinct - I can move at any time without regrets.

Uncle Ernie: A house is nice but, I would prefer a tent. Just give me a tent and let me wander the way we were meant to. Your aunt wouldn't be supportive of that, though.
Manda: Yeah, she seems like an indoor-house girl.

Third-Party Issues
I have had friends who were told by third-parties about their mates cheating. It's a strange situation, I believe, because you never know if someone is telling you your mate is cheating on you because they are trying to do the right thing or because they want to hurt someone with a serious accusation. Or even that they just have their facts wrong and the charming blond visiting your mate is actually a sibling. 

My advice remains the same. Face it head on.

Final Thoughts
I have known people who know their friend is cheating and are unsure if they should tell the mate in question. I encourage truthfulness. Besides, I don't think you should stand by and watch someone else get hurt. My logic was always why cheat? If you are so unhappy, leave the relationship. There is no point in screwing up your relationship, your mate's feelings and possibly the feelings of the person you are cheating with.

If you think about it and hone your skills, you can do a pretty good job at figuring out if your mate is being truthful by what is presented to you. However, if someone is really out to deceive you, they probably will. We don't play this dating game expecting to never be hurt or deceived. The point is, whatever happens, you can recover and move on. You can only do the best you can.

If your biggest worry is cheaters and you can't get past it, it's something you need to work on. Not everyone cheats and everything bad that happened in a past relationship shouldn't be the blueprint for the next one. You shouldn't be dragging your mate down with your insecurities. You also should be upfront about actions and consequences.