It can. It is best not to argue in front of the kids. Take it to another room or wait til the kids are a sleep. Make sure you are calm and try to discuss it. Kids will do as they see and if they see you all going at each others throat, they will be more willing to do the same.
My husband and I have good scotch irish tempers we can blow up easily. But we have learned not to blow in front of our child and were determined not to do it after he was born.
This is what we came up with as a means to deal with conflict. We make a list of our problems: what is bothering us, what we feel needs to be done, etc. We pass them too each other once a week then take a day or two to think over and consider the issues and then come up with our responses and discuss them. This allows us to rationalize and have time to consider the other persons point of view and we can resolve problems with out yelling and such. I don't know if this will work with you and your fiance, but it never hurts to ask.
If we learn by our mistakes, I am working on one hell of an education.
It affects kids for sure. My friend told me that her kids was always nervouse, difficult, has bad health as a result of her and her ex arguing and shouting in front of him.
They can even develope depression, not able to study, not wanting to study and so on.
It absolutely affects the kids. My ex-husband and I use to argue all the time and some of them were very heated. My daughter was around almost all of them. One of the last memories she has of the 3 of us living together was when he threw her chocolate milk at me. That was right before her 3rd birthday, she will be 6 next month.
There was an incident last summer where my husband (new one, not the ex), my daughter (who was 4), the baby (about 6 weeks old), and myself went to my sister's house to visit. Her and her husband fight a lot and they are yellers. Something happened and my BIL yelled at one of the kids very loudly. My daughter got so upset she was in tears and we had to take her home. On the car ride home she brought up "the chocolate milk" incident and wanted to know if "old daddy" (as she refers to him) still yells like that. We had to get into a whole different discussion of why she can't see her father anymore, but that's totally off topic.
My point is, even if the arguments are not that bad kids do feel the tension. The may not understand the feelings they are having but they know something is going on. It is best to do the arguing without the children around. Either have someone come over to watch them so you can discuss things outside of the house or wait for them to go to bed and talk quietly about it at the other end of the house. My husband and I will have disagreements, but we are very sure now not to do anything in front of the girls. I hate that I caused my daughter's uneasiness by fighting with my ex all the time. Kids need to feel secure and protected and it's impossible to feel that if the people they depend on the most cause a lot of tension.