Stairs is mad that she got made fun of by him is all. I think he had some good advice too.
It sucks in the beginning when it happens but it also sounds like you have some past issues that have come back to haunt you. Regardless of how many girls cheat or don’t cheat, they are not all like that and you can’t go into every relationship thinking that. Doing so will end you up at the same stop every time. I suggest you start looking at someone closer to your age. I don’t think girls at 22 or even 24 know what they want despite them thinking so; 25 and up is always a good rule of thumb.