I haven't dated many people, as I tend to be very selective and not interested in many people. The ones I am interested in it can be intense, and I have a hard time getting over it because I perceive an important connection, whether they do or not.
I have been with my current SO going on 7 years. While I have not cheated on him, and we are better than ever, there were some bumps on my end, of which he is not aware. I constantly felt restless at the beginning and like I should be out meeting other people. I went out to dinner with someone, and although it wasn't supposed to be a date (turns out he thought it was), I let him flirt with me and flirted back, and it turned out to definitely be close to a date. There are other times I have felt restless in my relationship and gotten a little too close to cheating in an impulsive way, like almost letting someone kiss me at a club, then stopping him at the last second. I thought about breaking up with my SO many times, when I was either restless and questioning staying in the same relationship, or depressed and felt like it was because I was bored in my relationship. Coming to terms with my moods as my own, and not part of the relationship has really helped, and I have not had those feelings of wanting to break up in some time.