Please help me to understand. My full sentence is
"... as someone who don't/ doesn't only love his...".
I have already tried them both and both sounds right.
Don't (do not) is the plural form, doesn't (does not) is the singular. She does, he doesn't, they do, they don't.
And, especially relevant to the question, someone does and someone doesn't.
-he/she/it doesn’t (does not).... example: “she doesn’t work outside the home after having her twins” -we/i/ they/you/ you all/ you guys don’t (do not).... example: “they don’t know how many hours we are working today.”