<human>: My girlfriend and I have been dating for 4 months now. In the beginning there was a lot of sparks and chemistry, and even to this day when we are together we have awesome chemistry and great times together.

However, even though I have a lot of feelings for her, I can't help myself from checking out and imagining myself with other women. Even when we're together and a hot girl passes I have to force myself not to check her out as I don't want to hurt my girls feelings by doing so. When I'm not with her, it's the same thing as I can't help but imagine what it'd be like if I was dating a cute girl I come across. It's not so much the sex with another person, but more of what my life would be like with another person. That's not to say it isn't great already, but I still get these urges and feelings that I want to experience others. This is also my first serious relationship.

That being said, I would never cheat on my girlfriend. I care about her a lot. She has told me she loves me, but I have not told it to her back as I want to know 100% I do before I say it. I do know that she would make a great partner and always be there for me in the future, in good health and bad. It makes me feel guilty that I can't reciprocate the same amount of love she has for me. 

Has anyone else been in a similar situation? Is it normal for a guy to feel like this in a serious relationship? Would it be worth it to break it off for these reasons? Or am I just being a dumb guy who should stick out for the long run?

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<bot>: Getting into my first serious relationship with a girl who I deeply care about, but I keep envisioning myself with other girls. Does this mean I should break it off?