SO and I: Karan, Karlan, Kyan, Ryly... So basically Karen (SO's mom's name) and Riley that could possibly work if you corrected the spellings.
My parents: Job, Jobert, Jodert, Roby, Rody
SO's parents: Leean, Karlee (different spelling of my name), Hoban, Kary, Karby, Koby, Kee
Patrayne (Patricia and Wayne, grandparents)
Terdra (Terry and Sandra, parents)
Altrick (Alberta and Patrick, great-grandparents)
Richia (Richard and Patricia, grandparents)
Joberta (Johnny and Alberta, great-grandparents)
Sandriver (Sandra and Oliver, my mom and her boyfriend)
Amanda + Justin (my boyfriend and me) = Justanda? Amustin?
Teresa + Joseph (my parents) = Tereseph? Joresa?
Richard + Elaine (boyfriend's parents) = Richaine? Elaichard?
Lillie + Donald (grandparents) = Lillnald? Dollie?
Verna + William (grandparents) = Velliam? Willna?
Donna + Tod (aunt/uncle) = Dod? Tonna?
Gregory + Ann (aunt/uncle) = Grann? Annory?
Janet + Tony (aunt/uncle) = Jony? Tanet?