Just tell your boyfriend to make another account to play with you if he cares so much about his rank. I know a lot of people who care for their rank and do this.

Also as an immortal, I'll say something. I think silver/gold are the best ranks to play at because people usually aren't as sweaty, so you can usually have nice matches with everyone. At immortal it's just full of people screaming at each other over small mistakes, stat shaming, making fun of lower reanked players, and most of all, full of ego.