Please understand some people are not all serious about this game ALL the time.. that's what ranked is for

I just spent a whole match arguing with someone cause me and my girl are trying to have a relaxed night playing a game we both love. We tried going down mid as mid and support and got cussed out the whole time.... I get its unorthodox but why cant we try new things its one match? (The carry even told us to unalive ourselves and to die)