For married couples do you guys value it the same or is it more for one person rather than both ?

I am not married and honestly I don’t think it’s for me maybe when I’m 30+ but I don’t judge. Here’s my thing because I see posts where someone’s Husband cheats right off the jump or starts flirting with women at the job and I also see this behavior in person. It seems like the female takes on the burden of their partner not being faithful. Personally I’m the type of person where if you cheat and I chose to move forward all of the pressure is on my partner not me because I didn’t do anything. It really sucks but my thing is before you get married of course being faithful is something you’ve probably discussed but do you discuss that before you get married like do you guys have the same expectations. My thing is marriage is a huge step and if someone steps out once or multiple times does that mean they don’t value marriage , possibly one partner values it more. I’m just confused as to why someone would get married just to cheat.It may seem stupid but I’m curious, I’ve told my boyfriend that I’m just not into the whole marriage thing he’s not against marriage but he’s cool with it so we have an understanding.ps I know women cheat too but I’m a straight female so can’t relate to that