Heh, yeah, I know… I used to work with teenagers with developmental disabilities and they were forever falling desperately in love with me. I used to get love letters, but once they stole the list of numbers from the office and started calling me. They were always asking me out on dates.
It is very difficult to understand for them if you are not very explicit. That obviously doesn’t mean that you can’t be kind.
Explain that you like enjoy seeing them when they come round to the shop once a week, but that you just want to be friends and no more. Also very kindly explain that you hope that they will stop asking such questions now, and that you will keep saying no. If they keep doing it, keep referring back to the conversation: “remember, we already talked about this. We are just friends, and I am not going on a date with you.” At the same time, don’t over-emphasise the friendship, because they will want to hang out more. State firmly that you like seeing them once a week at the shop and you want to keep it that way.
It’s a tough situation. Especially when you realise how incredibly hard finding a partner is for them. This was a constant struggle for the kids I worked with, and really not too easy to solve. They so often tend to fall for people not within their spectrum of intelligence, who are subsequently not interested. The pool they are fishing in is just far smaller and more complicated, so it’s really difficult to find someone. Then when they do the trouble really starts: they want to live together, have children. Oh dear.
Anyway, as others said: be kind, firm and explicit. Don’t be afraid to become very explicit if that is necessary, eg: “when you are in love you do different things together, like touch, kiss and have sex. But I don’t feel that way about you, I don’t want that.” Not to begin with, but just as a warning that the conversation might go there.
You might want to be aware that they could behave inappropriately. I don’t want to worry you, but it might happen. It can be very difficult for them to judge these things. As a precaution, be very clear and firm about any touching, even if it seems innocent. Things like kissing your hand or hugging you. Ask them to leave if they start crossing any boundaries, and try to bring it up with the people of their residence.