The NPC promised sim shows up to ask me to be his girlfriend. I generally play girl sims, so haven't seen it done with genders swapped.
Just had Kiyoshi ask to hang out, and he asked to be boyfriend again. Accepting doesn't change the relationship, as previously stated.
OK, started a new save with a teen boy. Exchanged promise rings with Rashidah Watson on the first date, got a Want to Ask Rashidah to be Girlfriend on the second. I'll have to wait a bit to see if she shows up asking to become her boyfriend, as that happens when they ask to hang out.
Second day, after school, Rashidah initiated a stay over with my sim, and almost immediately after showing up messaged asking to hang out (whole separate bug) and asked my sim to be her boyfriend, so same bug applies to both boys and girls. I don't play same-sex couples, so forgive me if I don't test other permutations.
The NPCs always initiate the ask to be boyfriend/girlfriend interaction while promised; the player character doesn't have the option (not on the pie menu under either Romance or Affection.) Rashidah inititiated the stayover, the hang out, and the ask to be her boyfriend.
