Feelings for another.

Ok so i have been with my partner for 6 years in September and we have a 2 1/2 year old. We found each other on fb. Oh and we new each other from school. We decided to meat he was great and is great. He worker hard to keep himself in shape and he looked fantastic. But now he has well got too comfortble put a little Wright on doesn't work out as much. Don't get me wrong I love him to bit no water what side as it is on the inside that matters the most not the out. But for a while now I have found my self think about his younger brother. He 3 years younger then me. He's is well he's is in fantastic shape. Very pleasing on the eyes gorgeous smile that would make any women go week at the kneese. We both have the same dry sens of humer. We can even finish each others sentencis. The list is endless. But just lately I have been thinking about him alot more and wondering if I chosse the wrong brother. I would never act on my feeling as it would not be Wright especially has he is in a relationship and has children with his partner. But I just don't know what to do. My partner and I don't seen his brother that much but just when I think that the thought are gone it was just a faze a silly little crucsh that we all get from time to time. Then I see a pic at of him or i see him at a family even and the thoughs and feeling come back. I have no idea how he feels and I woulden't dream of asking for fear of loosing the friedship we do have well unless I was no longer with his brother and he was not with his partner then maybe. But I love may partner and I want to be with him. Oh Help ladis please. Have you ever had a crucsh on some one you should not have? What did you do? How did you deal with it?