Amyjo...(Hi stranger! )....I have just three words for you...
MARRIED, NOT BURIED!!!!
This situation makes you uncomfortable because he is involved with your DH, while the classmates aren't. It's all logistics. You may feel guilty because you're afraid your DH might pick up on how the other guy makes you feel. Trust me....there is NO such thing as the perfect man, and as gorgeous as this guy is, he probably lives in a pigsty and clips his toenails at the dinner table. ( Did that help? ) Really, though...what you're feeling is perfectly normal.
I actually have a close male friend that DH knows about, and I go out to dinner occasionally with this friend, or meet for other things. This friend and I actually addressed the whole male/female can't be just friends thing, and discovered that once we talked about it, we actually CAN be just friends. Neither of us wanted to risk our friendship for a short-term relationship, marriages aside. Personally, I could never be unfaithful to my hubby. But it's nice to know that you're still attractive to other men!
I think that we tried everything between our 5th and 6th year of marriage. I can safely say Open marriage doesn't work for me and I have been married for 12 years, and 9 of them have been good!;-)
Alot of his "bad" attributes are some of the reasons DH and I dated for 7 years before we got married.... He had "alot" of the same qualities that "the GUY" has, too PICKY to save his life, the perfectly clean car, the perfectly ironed clothes, the perfectly spottless house, every thing his way or the high-way... Well I eventually beat my DH in to submission so to speak and got him trained... This guy just hasn't found the "right" woman to get him trained or vice versa.
His "bad" attributes are basically he is a self center SOB with a cute butt and a killer smile with style to bootand attitude that just gives him this aura. I really think that most of my problem is that he works with DH and that I am around him on occasion. DH has this homing device for what I am attracted to and he knows my "type" therefore he is probably fully aware that this guy gets to me. Hence, I am more on edge to make sure that I don't flirt or make my presences known. Probably why it is bugging me so much....
I have heard this saying in the past and fully think it applies here.
"It doesn't matter where you get your appetite, as long as you eat at home"
I agree with what everyone's already said! Just wanted to say I certainly know exactly what you mean Amy...I have had a crush on someone for about a year, it's just in my mind and I don't feel guilty - hey, we are human, aren't we? I use the crush sometimes to help me stay on my diet/exercise thing, cuz I want to look good from a distance! I would NEVER do anything, would never want to - and never talk about it (well, except here I guess!)
I was just going to chime in with the "it doesn't matter where you get your appetite..." and you said it already. Dang!
Words to live by in my opinion. When we were married almost 17 years ago I talked with my husband about this because you're going to be attracted to someone along the way. I probably see a dozen people a day I wouldn't mind having a go with if my circumstances were different. When I've told my friends that I talked with my husband about this before we were married they were shocked and almost all of them have gone on to have disastrous affairs. And it's because their feelings caught then off guard and they didn't know what to do so they acted on them.
Awareness is everything.
There's a lot of luscious men [and women!] out there. You're quite normal!!! Enjoy the view!
I've ventured down this road and it is not a pleasant one. Yes, it is normal to be attracted to other people while married. However, if the attraction becomes an ongoing fantasy or your thoughts dwell on this other person when they should be focused on your spouse... than it it is not healthy. I have come to the determination that I am either contributing to my marriage in a positive way or a negative way at any given moment. As tempting and scrumptious a crush or fantasy on another person is... it can only lead to heartache and pain if allowed to take its course. Those boundaries we draw in our brain seem to be redrawn over and over again as the flirt turns into an admission of feelings and the feelings develop into a relationship and the excitement and intensity build and you want to push the envelope even further... and eventually to something physical. Thankfully I stopped before my "crush" became too physical... but an emotional affair is just as devastating. In the end it was definitely not worth the pain and tears and it almost ruined my marriage. Thankfully now my husband and I are closer than ever. Although it is normal to be attracted to others, just be aware that it is like playing with fire. I found that what I was really attracted to was the affirmation I received knowing another man was attracted to me... it had little to do with the other guy and everything to do with my insecurities. I guess you just need to listen to your gut feelings and trust your feelings of guilt and discomfot... it sounds like you intuitively know there is something not right about the situation. Those feelings are not there by accident.
It is absolutely normal to find some one attractive, just because you are married, it doesn't mean you are dead.
Now acting on your feelings is a horse of another color
Just remember why you fell in love w/your husband in the first place and you will see this other guy in another light. Besides, he may look good on the outside but maybe he's a cronic nose picker or his wedding tackles may be itsy bitsy....ROFLMFAO !!!!
Don't be so hard on yourself, we all feel this way about someone.
)....I have just three words for you...
and got him trained... This guy just hasn't found the "right" woman to get him trained or vice versa. 
Hmmmm...
