Yes it's a bit messed up sometimes, one of mine got asked to prom by his aunt and I said yes, she kissed him there but it didn't change the relationship thankfully.
If I ever see an EA generated babysitter entering the building I reset them, which usually results in a message saying my sim at the prom got refused a dance and will be dancing alone for the night.
It would be nice if it did check relationships, so no family love interests and if you already have a romantic interest it gets them to invite you, or asks to go steady at the dance not somebody you barely know or a random babysitter.
In saying that one of my dynasty spares got an awesome husband from prom, a babysitter but as it's a challenge I couldn't reset him just to avoid it, I really liked him although he had the npc aging bug and was a generation older when she invited him over after graduation
So far i've had just one perfect prom, I say perfect because her RI asked her, he turned up on time and got in the limo in his formal gear, then according to the pop up message while they danced he stared deep into her eyes and then kissed her, so sweet. Usually they don't show up, or fail to get in the car, or she ends up going alone if I don't do the asking then I have the dread it will pair her up with the wrong person and not her RI
